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HenryÆs law constants and infinite dilution activity coefficients of cis-2-butene, dimethylether, chloroethane, and 1,1-difluoroethane in methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol
Yoshimori Miyano; Takahiro Kobashi; Hiroshi Shinjo; Shinya Kumada; Yusuke Watanabe; Wataru Niya; Yoko Tateishi
HenryÆs law constants and infinite dilution activity coefficients of cis-2-butene, dimethylether, chloroethane, and 1,1-difluoroethane in methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol in the temperature range of 250K to 330K were measured by a gas stripping method and partial molar excess enthalpies were calculated from the activity coefficients. A rigorous formula for evaluating
Total pressure measurements for benzene with 1-propanol, 2-propanol, 1-pentanol, 3-pentanol, and 2-methyl-2-butanol at 313.15 K
Jonathon M Rhodes; Tyson A Griffin; Michael J Lazzaroni; Venkat R Bhethanabotla; Scott W Campbell
Total pressure measurements at 313.15K are reported for binary systems of benzene and 1-propanol, 2-propanol, 1-pentanol, 3-pentanol, and 2-methyl-2-butanol. The results are interpreted by an extended form of the Kretschmer¢Wiebe association model, in which it is assumed that linear alcohol chains may solvate with a single benzene molecule.
Vapor¢liquid equilibria and critical points for the carbon dioxide +1-pentanol and carbon dioxide +2-pentanol systems at temperatures from 332 to 432 K
G Silva-Oliver; Luis A Galicia-Luna; S. I Sandler
Vapor¢liquid equilibria and critical points of the systems: carbon dioxide+1-pentanol at (333.08, 343.69, 374.93, 414.23 and 426.86K) up to 18.6MPa and carbon dioxide+2-pentanol at (332.10, 343.61, 374.15, 397.56, 422.28 and 431.78K) up to 15.7MPa are reported at compositions near the critical point. An apparatus capable of measurement up to 60MPa and 523K based on the static-analytic method has been used
Nucleation of 1Pentanol Using a Thermal Diffusion Cloud Chamber
Anne Bertelsmann; Richard H. Heist
We report results of new nucleation experiments involving 1-pentanol with hydrogen as the background gas obtained from constant pressure critical supersaturation measurements and from constant temperature critical supersaturation experiments utilizing the high-pressure diffusion cloud chamber. We continue to observe significant background gas effects upon nucleation that we have reported previously; and we briefly discuss the important issue of stability (the
Dilution method study on the interfacial composition, thermodynamic properties and structural parameters of W\\/O microemulsions stabilized by 1-pentanol and surfactants in absence and presence of sodium chloride
Bidyut K. Paul; Debdurlav Nandy
The phase behaviors, interfacial composition, thermodynamic properties and structural characteristics of water-in-oil microemulsions under varied molar ratio of water to surfactant (?) at 303 K and also by varying temperatures at a fixed ?(=40) by mixing with 1-pentanol and decane or dodecane in absence and presence of sodium chloride have been studied by the method of dilution. The surfactants used
Enantioselective acylation of R-2-pentanol in a solid/gas reactor catalysed by lipase B from Candida antarctica.
Paris-Sud XI, Universitķ de
from Candida antarctica. Valķrie LEONARD, Sylvain LAMARE, Marie-Dominique LEGOY and Marianne GRABER reaction carried out in liquid systems. This reaction was catalysed by lipase B from Candida antarctica-added organic component on the other hand. Keywords (five): Lipase B from Candida antarctica; enantioselectivity
Formation of the metabolic intermediate 2,4,4-trimethyl-2-pentanol during incubation of a shape Sphingomonas sp. strain with the xeno-estrogenic octylphenol
Tom Tanghe; Willem Dhooge; Willy Verstraete
Degradation of branched octylphenol was studied in abacterial culture of a Sphingomonas sp. strain.Octylphenol is considered to be the most stabledegradation intermediate formed from the correspondingnonionic octylphenol polyethoxylates surfactantsduring biological wastewater treatment. Sinceoctylphenol can exert estrogenic effects in wildlife,a detailed study of its biodegradation is warranted.The aerobic microbiological transformation ofoctylphenol was examined with and without the additionof the easily assimilable
Liquid chromatographic analysis of coal surface properties. Final report, September 1991--February 1995
Kwon, K.C.
Experiments on equilibrium adsorption loadings of various probe compounds on 60-200 mesh Illinois {number_sign}6 coal (PSOC-1539), Adaville {number_sign}1 coal (PSOC-1544), Wyodak coal (PSOC-1545) and Pittsburgh {number_sign}8 coal (PSOC-1549) were performed. the probe compounds include m-cresol, p-cresol, o-cresol, phenol, n-octanol, n-heptanol, n-propanol, isopropanol n-butanol, s-butanol, 2-butanol, t-butanol, 2-naphthol, cyclohexanol, 2-methyl-1-pentanol (2M1P), 4-methyl-2-pentanol (4M2P), benzene and toluene. Equilibrium adsorption of various probe compounds on the coals were measured with the inverse liquid chromatography method. Experiments on flotation of various 60-200 mesh treated coals such as Illinois {number_sign}6 coal (PSOC-1539), Adaville {number_sign}1 coal (PSOC-1544), Wyodak coal (PSOC-1545) and Pittsburgh {number_sign}8 coal (PSOC-1549) were performed. The chosen coals were treated with steam, nitrogen and air at 1 atm and 125-225{degrees}C for 24 hours. The coals were treated with water as well as 20-1000 ppm aqueous alcohol solutions for 3-24 hours at 150-225{degrees}C. The coals also were treated with 20-ppm alcohol aqueous solutions for 1-24 hours at the 0.002-g/min mass flow rate of alcohol aqueous solutions and at 225{degrees}C. Flotation experiments were conducted with a 500-cm{sup 3} batch-type micro flotation apparatus, introducing nitrogen at the bottom of the apparatus. This final report was prepared with the experimental data obtained during the period of September 1991-March 1994.
Reactivity of Individual Organolithium Aggregates a RINMR Study of n-Butyllithium and 2-Methoxy-6-(methoxymethyl)phenyllithium
Reich, Hans J.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S-19 1-Phenyl-1-pentanol-Phenyl-3-(trimethylsilyl)prop-2-yn-1-ol (6a) . . . . . . . . . . . . . . . . . . . . . . . . . . S-22 1-Phenyl-3-(triphenylsilyl)prop-2-yn-1-ol (6b) . . . . . . . . . . . . . . . . . . . . . . . . . . S-22 1
Ultrasonic investigations of binary liquid mixtures of 1,2-propanediol with 1-alkanols at 298.15 K
NASA Astrophysics Data System (ADS)
Kopi?ska-Pragnacy, M.; Zorebski, E.
The results of ultrasonic investigations of binary liquid mixtures of 1,2-propanediol with three 1-alkanols, i.e., 1-hexanol, 1-pentanol, and 1-butanol at the temperature 298.15?K are presented. Based on the phase speed of ultrasound values (measured by the pulse-echo-overlap method at 2.18?MHz) and excess molar volumes (taken from the literature), the excess values of the isentropic compressibility coefficients were calculated. Their composition dependencies were expressed by the Redlich-Kister polynomials. It appears that mixing of 1,2-propanediol with 1-hexanol, 1-pentanol, and 1-butanol results in enhanced rigidity in sequence: 1-hexanol, 1-pentanol, and 1-butanol. A comparison with volume and enthalpy changes upon mixing as well as deviations of the speed of ultrasound are discussed too.
JASPERSE CHEM 360 TEST 1 VERSION 3 Reactions involving Alcohols
Jasperse, Craig P.
1 JASPERSE CHEM 360 TEST 1 VERSION 3 Reactions involving Alcohols 1. 2-Methyl-3-pentanol is classified as: (3 points) a. a primary alcohol b. a secondary alcohol c. a tertiary alcohol d. none;6 10. Design syntheses of the following, starting from alcohols of 4 carbons. (7 points each) O #12;
Thermal diffusion cloud chamber: new criteria for proper operation
Richard H Heist; Anne Bertelsmann; Daniel Martinez; Yuk Fung Chan
We report results of new nucleation experiments involving 1-pentanol with hydrogen as the background gas obtained from constant temperature critical supersaturation experiments utilizing the high-pressure diffusion cloud chamber. We have observed significant background gas effects on vapor nucleation that differ somewhat from that we have reported previously. In this paper, we discuss the important issue of stability (the absence of
Preparation and Characteristics of a New Antibacterial Cotton Fiber Bonding a Gemini-type Quaternary Ammonium Salt
Fei Zhou; Jian-Hua Zhang; Xian-Feng Sun; Qin-Qin Wang; Yu-Han Sun
Two kinds of antibacterial cotton fiber (called as C14 and Ct) were prepared by bonding a gemini-type quaternary ammonium compound with a hydroxyl group in their spacer chain (1,5-bis(tetradecyl dimethyl ammonium iodide)-3- pentanol (called as DAP14)) and a mono-type quaternary ammonium compound (N-tetradecyldimethyl (3-trimethoxysilylpropyl) ammonium chloride (called as TMMP)), respectively, to the surface of cotton fiber using a coupling agent,
Effect of aliphatic alcohols as mobile phase modifiers on separation of phenylurea and phenoxyalkyl acid herbicides by micellar electrokinetic capillary chromatography
Adriana Farran; Santiago Ruiz
The rapid and single separation of a mixture of neutral and ionic herbicides, five phenylurea (diuron, fenuron, linuron, monolinuron and monuron) and four phenoxyalkyl acids (dichlorprop, 2,4-D, 2,4,5-T and 2,4-DB) was achieved by micellar electrokinetic capillary chromatography (MECC) after different aliphatic alcohols (1-heptanol, 1-hexanol, 1-pentanol, 1-butanol and methanol) were added to a phosphate buffer (0.02 M) containing 0.05 M sodium
Thermal diffusion cloud chamber-new criteria for proper operation
Richard H. Heist; Daniel Martinez; Yuk Chan; Anne Bertelsmann
We report results of new nucleation experiments involving 1-pentanol with hydrogen as the background gas utilizing the high-pressure diffusion cloud chamber (HPCC). We discuss the important issue of buoyancy-driven convective motion and cloud chamber operation, and we focus on the lower total pressure limit required for stable chamber operation. We provide, for the first time, an empirical procedure for determining
Vapour¢liquid equilibria, azeotropic data, excess enthalpies, activity coefficients at infinite dilution and solid¢liquid equilibria for binary alcohol¢ketone systems
Rima Abbas; J³rgen Gmehling
Isothermal vapour¢liquid equilibria (VLE), solid¢liquid equilibria and excess enthalpies have been measured for the systems cyclohexanone+cyclohexanol and 2-octanone+1-hexanol. Additionally in this paper binary azeotropic data at different pressures for 1-pentanol+2-heptanone and 1-hexanol+2-octanone have been determined with the help of a wire band column. Furthermore activity coefficients at infinite dilution for methanol, ethanol, 1-butanol and 1-propanol in 2-octanone at different temperatures
The relationship between terminal functionalization and molecular weight of a gene delivery polymer and transfection efficacy in mammary epithelial 2-D cultures and 3-D organotypic cultures
Nupura S. Bhise; Ryan S. Gray; Joel C. Sunshine; Soe Htet; Andrew J. Ewald; Jordan J. Green
Non-viral gene delivery vectors were developed for efficient gene transfer to hard-to-transfect mouse mammary epithelial cells. Ten modified versions of the same base poly(beta-amino ester), poly(1,4-butanediol diacrylate-co-5-amino-1-pentanol), were tested in both traditional 2-D monolayer and in 3-D organotypic cultures. The polymers self-assembled with plasmid DNA encoding enhanced green fluorescent protein to form nanoparticles (?100Ānm) used to transfect the cells. Nanoparticle
Binary mutual diffusion coefficients of aqueous alcohols. Methanol to 1-heptanol
Ling Hao; Derek G. Leaist
Mutual diffusion coefficients, measured by Taylor dispersion at 25 C, are reported for binary aqueous solutions of methanol, ethanol, isomeric propanols and butanols, 1-pentanol, 1-hexanol, and 1-heptanol. Limiting diffusion coefficients (D┬░) for the 1-alkanols are found to decrease with alcohol molar volume V approximately as VŌü╗┬╣┬▓. Although values of D┬░ for aqueous 1-propanol and 2-propanol are nearly identical within experimental
Contributions of additional group interaction parameters through limiting activity coefficient measurements on aliphatic alcohols, aromatic hydrocarbons, ketones and an ester in tetrahydroxyethylethylenediamine and tetraethylene pentamine
S. M. Ashraf; M. Ramakrishna; D. H. L. Prasad; M. Bhagwanth Rao
Gas chromatographic method has been used to measure the limiting activity coefficient of some aliphatic alcohols (ethanol, 1-propanol, 1-butanol and 1-pentanol), aromatic hydrocarbons (benzene, toluene, ethylbenzene, o-xylene and p-xylene), ketones (acetone and methylisobutylketone), ethylacetate and chlorobenzene in tetrahydroxyethylethylenediamine (THEEDA) and tetraethylpentamine (TEPA). The measurements involving THEEDA have been used to derive UNIFAC group interaction parameters for seven new pairs, while
Inhibition of receptor-mediated noradrenaline release from the sympathetic nerves of the isolated rabbit heart by anaesthetics and alcohols in proportion to their hydrophobic property.
G÷thert, M; Kennerknecht, E; Thielecke, G
The actions of anaesthetics (diethyl ether, enflurane, chloroform, methoxyflurane) and alcohols (ethanol, 1-propanol, 1-butanol, 1-pentanol) on the noradrenaline release from (and uptake into) the sympathetic nerve terminals were studied in isolated rabbit hearts perfused with Tyrode solution at constant flow rate. The noradrenaline in the perfusate was assayed spectrofluorimetrically. 1. Ethaonol, 1-propanol, 1-butanol and all anaesthetics (at concentrations which decreased by more than 65% the noradrenaline output in response to activation of the nicotinic receptors) did not significantly affect the spontaneous noradrenaline output. Only 1-pentanol (3.75 X 10(-3) M) caused an increase in spontaneous noradrenaline output. 2. The uptake of exogenous noradrenaline from the perfusion fluid into the sympathetic nerve terminals was not influenced by the anaesthetics and alcohols (at concentrations which decreased by more than 65% the noradrenaline output evoked by stimulation of the nicotinic receptors). 3. All anaesthetics and alcohols caused a concentration-dependent inhibition of the noradrenaline release in response to activation of the nicotinic receptors on the nerve terminals by 1,1-dimethyl-4-phenylpiperazine or acetylcholine in the presence of atropine. The concentrations of the compounds which decreased the noradrenaline output by 50% were as follows: diethyl ether: 5.1 X 10(-3) M; enflurane: 2.9 X 10(-4) M; chloroform: 2.6 X 10(-4) M; methoxyflurane: 3.8 X 10(-5) M; ethanol: 1.5 X 10(-1) M; 1-propanol: 1.9 X 10(-2) M; 1-butanol: 6.0 X 10(-3) M; 1-pentanol: 1.2 X 10(-3) M. PMID:940595
Use of labeled compounds to study the mechanism of flavor formation in oxidizing fats
S. T. Michalski; E. G. Hammond
2-14C-Hexanal,trans, trans-5-14C-2,4-decadienal, 4-14C-1-octen-3-ol, 4-14C-1-octen-3-one and 1-14C-1-pentanol were synthesized and added to freshly deodorized soybean oil in concentrations ranging from 7¢125 ppm. The soybean\\u000a oil was oxidized, and the fate of the labeled compounds was followed. Hexanal was converted to hexanoic acid especially at\\u000a 50 C or higher. The 2,4-decadienal was converted to 2,4-decadienoic acid at room temperature, and heptenal, 2-octanal,
Diffusion in associated and non-associated homologous seriesĀ
Alhamid, Khalid A.
Akgerman The infinite dilution diffusion coefficients of the homologous series of primary alcohols methanol, ethanol, 1 ? propanol, 1-pentanol, 1-heptanol, 1-decanol, and 1-tetradecanol have been measured in the solvents n-octane and 1 ? octanol... of Diffusivity VI CONCLUSION NOMENCLATURE LITERATURE CITED nt vt vl1 . 1X 4 4 5 6 14 23 24 25 28 29 30 32 32 33 61 63 65 TABLE OF CO~S (Continued) APPENDIX A: SUMVIARY OF RELEVANT LITERATURE DATA ON DIFFUSION COEFFICIENTS AT INFINITE...
Regioselective alkane hydroxylation with a mutant CYP153A6 enzyme
Koch, Daniel J.; Arnold, Frances H.
Cytochrome P450 CYP153A6 from Myobacterium sp. strain HXN1500 was engineered using in-vivo directed evolution to hydroxylate small-chain alkanes regioselectively. Mutant CYP153A6-BMO1 selectively hydroxylates butane and pentane at the terminal carbon to form 1-butanol and 1-pentanol, respectively, at rates greater than wild-type CYP153A6 enzymes. This biocatalyst is highly active for small-chain alkane substrates and the regioselectivity is retained in whole-cell biotransformations.
Synergic effects in the extraction of paracetamol from aqueous NaCl solution by the binary mixtures of diethyl ether and low molecular weight primary alcohols
NASA Astrophysics Data System (ADS)
Nikoli?, G. M.; Äivkovi?, J. V.; Atanaskovi?, D. S.; Nikoli?, M. G.
Liquid-liquid extraction of paracetamol from aqueous NaCl solutions was performed with diethyl ether, 1-propanol, 1-butanol, isobutanol, 1-pentanol, and binary mixtures diethyl ether/1-propanol, diethyl ether/1-butanol, and diethyl ether/isobutanol. Among the pure solvents investigated in this study best extraction efficacy was obtained with 1-butanol. Synergic effects in the extraction with binary mixtures was investigated and compared with some other systems used for the extraction of poorly extractable compounds. Results obtained in this study may be of both fundamental and practical importance.
Enantioselective analysis of secondary alcohols and their esters in purple and yellow passion fruits.
Strohalm, Hedwig; Dregus, Mßrta; Wahl, Astrid; Engel, Karl-Heinz
The enantiomeric compositions of the acetates, butanoates, hexanoates, and octanoates of the secondary alcohols 2-pentanol, 2-heptanol, and 2-nonanol were determined in yellow (Passiflora edulis f. flavicarpa) and purple (Passiflora edulis Sims) passion fruits. The compounds were isolated by means of simultaneous distillation-extraction. Enantiodifferentiation was performed via multidimensional gas chromatography using heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-beta-cyclodextrin as chiral stationary phase. The series of homologous 2-alkyl esters, which are typical constituents of purple passion fruits, were shown to be present as nearly optically pure (R)-enantiomers. The proportions of the (S)-enantiomers varied in different batches and were dependent on the alcohol moieties of the esters. For minor amounts of esters detected in yellow fruits, the (R)-enantiomers were also dominating. However, the enantiomeric excesses were significantly lower than in the purple variety. Enantioselective analysis of the free alcohols revealed that 2-heptanol exhibited opposite configurations in purple and yellow passion fruits. A similar phenomenon was observed for 2-pentanol, which was present in the yellow fruits as a nearly racemic mixture. Data determined in extracts obtained by other techniques (liquid-liquid extraction, vacuum headspace technique) showed that the isolation procedure had no significant impact on the enantiomeric ratios. PMID:18004806
Enhancement of nitrate-induced bioremediation in marine sediments contaminated with petroleum hydrocarbons by using microemulsions.
Zhang, Zhen; Zheng, Guanyu; Lo, Irene M C
The effect of microemulsion on the biodegradation of total petroleum hydrocarbons (TPH) in nitrate-induced bioremediation of marine sediment was investigated in this study. It was shown that the microemulsion formed with non-ionic surfactant polyoxyethylene sorbitan monooleate (Tween 80), 1-pentanol, linseed oil, and either deionized water or seawater was stable when subjected to dilution by seawater. Desorption tests revealed that microemulsion was more effective than the Tween 80 solution or the solution containing Tween 80 and 1-pentanol to desorb TPH from marine sediment. In 3Āweeks of bioremediation treatment, the injection of microemulsion and NO3 (-) seems to have delayed the autotrophic denitrification between NO3 (-) and acid volatile sulfide (AVS) in sediment compared to the control with NO3 (-) injection alone. However, after 6Āweeks of treatment, the delaying effect of microemulsion on the autotrophic denitrification process was no longer observed. In the meantime, the four injections of microemulsion and NO3 (-) resulted in as high as 29.73Ā% of TPH degradation efficiency, higher than that of two injections of microemulsion and NO3 (-) or that of four or two injections of NO3 (-) alone. These results suggest that microemulsion can be potentially applied to enhance TPH degradation in the nitrate-induced bioremediation of marine sediment. PMID:25529494
Population growth kinetics of Tetrahymena pyriformis exposed to selected nonpolar narcotics.
Bearden, A P; Gregory, B W; Schultz, T W
This study describes effects of selected nonpolar narcotics of varying hydrophobicity (quantified by the 1-octanol-water partition coefficient, log Kow) and molecular structure on the population growth kinetics of the freshwater ciliate Tetrahymena pyriformis. The response of Tetrahymena exposed to different nonpolar narcotics varied from a change in generation time to a change in lag phase with similar generation time compared to control. Two narcotics with high (>3.00), intermediate (>0.00 and <3.00), and low log Kow (<0. 00) values were tested. Growth of Tetrahymena inhibited up to 85% by the high log Kow toxicants (2-decanone and butylbenzene) grew with similar rates as the control, but exhibited increased lag time, suggesting that the protozoan became acclimated to toxicant stress. Results from growth of Tetrahymena in the low log Kow toxicants (ethanol and acetone) indicate an increased generation time with increasing concentration. Cells inhibited by the intermediate log Kow chemicals, 1-pentanol and anisole, exhibited a response that was a combination of the previously mentioned two contrary responses. Cells inhibited <35% with 1-pentanol and <50% with anisole grew with similar generation times as control flasks, whereas in cells inhibited >35% or >50%, respectively, the doubling times were longer than control growth. PMID:9419258
Biphasic aqueous/organic biotransformation of acetaldehyde and benzaldehyde by Zymomonas mobilis pyruvate decarboxylase.
Rosche, Bettina; Breuer, Michael; Hauer, Bernhard; Rogers, Peter L
Zymomonas mobilis pyruvate decarboxylase (PDC) transformed acetaldehyde and benzaldehyde into (R)-phenylacetylcarbinol (PAC), the precursor for the synthesis of ephedrine and pseudoephedrine. Organic solvents were screened for a biphasic biotransformation with the enzyme in an aqueous phase and the toxic substrates delivered through the organic phase. In the absence of substrates a second phase of 1-pentanol, hexadecane or MTBE (methyl tertiary-butyl ether) stabilized the PDC activity in comparison to a control without added solvent. Organic phase solvents for optimal PAC production had partitioning coefficient (log P) values between 0.8 and 2.8 (production of more than 8 mg PAC/ U PDC), however there was no correlation between enzyme stability and log P. Best PAC formation was observed with the eight tested alcohols, which in contrast to the other solvents allowed lower initial concentrations of toxic acetaldehyde (54-81 mM) in the aqueous phase. 1-pentanol, 1-hexanol, and isobutanol resulted in the highest specific PAC production of 11 mg PAC /U PDC. Without the addition of an organic phase, only 1.2 mg/U was formed. PMID:15162454
Correlation and prediction of thermodynamic properties of binary mixtures from perturbed chain statistical associating fluid theory
NASA Astrophysics Data System (ADS)
Almasi, Mohammad
Densities and viscosities for binary mixtures of Diethanolamine (DEA) + 2 alkanol (2 propanol up to 2 pentanol) were measured over the entire composition range and temperature interval of 293.15-323.15 K. From the density and viscosity data, values of various properties such as isobaric thermal expansibility, excess isobaric thermal expansibility, partial molar volumes, excess molar volumes and viscosity deviations were calculated. The observed variations of these parameters, with alkanols chain length and temperature, are discussed in terms of the intermolecular interactions between the unlike molecules of the binary mixtures. The ability of the perturbed chain statistical associating fluid theory (PC-SAFT) to correlate accurately the volumetric behavior of the binary mixtures is demonstrated.
The effects of maturity on chilli pepper volatile components determined by SDE, GC-MS and HPLC.
Liu, Rong; Xiong, Ke; Dai, Xiongze; Wang, Li; Liu, Zhimin; Xue, Wentong
The volatile components of a Chinese chilli pepper (Capsicum annuum L. var. longum Sendt) were identified at different levels of ripeness. The peppers at the green, ripening, and full color stages were investigated by simultaneous distillation extraction (SDE) combined with gas chromatography and mass spectrometry (GC-MS). Principal component analysis (PCA) was used to analyze the main factors at each of the stages studied. Eighty-one volatile components were identified and quantified in this study. Twenty-two compounds were found at the green stage, forty-four at the ripening stage, and sixty-one at the full color stage. Qualitative and quantitative discrepancies were observed at the different levels of ripeness. Hexanal, 2-hexenal and propanoic acid-2-methyl-hexyl ester were the most abundant components at the green stage, while 2-pentanol was important at the ripening stage, and 3-hexen-1-ol was related to the full color stage. PMID:20614840
Chemoenzymatic solvent-free synthesis of 1-monopalmitin using a microwave reactor.
Torregrosa, Rubķn; Balcells, Mercķ; Torres, Mercķ; Canela-Garayoa, Ramon
An environmentally friendly method for the synthesis of 1-monopalmitin has been developed. The procedure consists of a two-step, solvent-free chemoenzymatic reaction. In the first step, palmitic acid is esterified with solketal (4-hydroxymethyl-2,2-dimethyl-1,3-dioxolane) using Novozym 435 by both conventional heating and microwave irradiation. The use of a microwave reactor allows the enzymatic synthesis of the intermediate compound with a similar yield as that achieved using conventional heating. In the second step, 1,2-acetonide-3-palmitoyl glycerol is cleaved to yield 1-monopalmitin by means of a cation-exchange resin and water or aliphatic alcohols as hydrolytic reagent in solvent-free conditions. The hydrolysis was accomplished in 15 min at 85 degrees C. The best yield was obtained using 1-pentanol. We conclude that the yield achieved depends on the batch and nature of the cation-exchange resin used as catalyst. PMID:25233581
Solvent optimization for niacinamide adsorption on organo-functionalized SBA-15 mesoporous silica
NASA Astrophysics Data System (ADS)
Moritz, Micha?
This work describes the application of organo-modified SBA-15 siliceous materials as the carrier for niacinamide. The surface functionalization of SBA-15 by a grafting strategy with triethoxyphenylsilane, triethoxy(4-methoxyphenyl)silane, triethoxymethylsilane and (3-mercaptopropyl)trimethoxysilane as modifying agents has been successfully achieved. The adsorption process was performed in acetonitrile, methanol, 2-propanol, 1-pentanol and ethyl acetate. The obtained results indicated a promote niacinamide adsorption on sulfopropyl-modified (119 mg/g) and non-modified (78 mg/g) SBA-15 from ethyl acetate. The pure and derivatized SBA-15 products have been characterized by elemental analysis, thermogravimetry, nitrogen adsorption and diffuse reflectance UV spectroscopy. After niacinamide adsorption the textural parameters of mesoporous carriers such as BET surface area, pore volume and microporosity were reduced. The mesoporous matrices loaded with niacinamide exhibited prolonged-release kinetics of this vitamin, especially from sulfopropyl-modified SBA-15 carrier.
Nanostructured fluids based on propylene carbonate/water mixtures.
Palazzo, Gerardo; Fiorentino, Daniela; Colafemmina, Giuseppe; Ceglie, Andrea; Carretti, Emiliano; Dei, Luigi; Baglioni, Piero
The microstructure of aggregates formed by sodium dodecyl sulfate (SDS) and 1-pentanol in mixtures of water and a polar aprotic solvent (propylene carbonate, PC) was investigated by means of pulsed gradient spin-echo NMR, dynamic light scattering, viscosity, and conductivity measurements. PC partitions itself between micelles and aqueous bulk. The fraction of micellized propylene carbonate remains constant along PC-dilution, and the phase separation takes place when the composition of continuous phase attains the PC/water miscibility gap. The micellized PC is present mainly in the micelle's palisade and strongly increases the total interfacial area, thus acting as a cosurfactant. At high PC content, the system is composed by very small aggregates (around 10 A in radius) made by few SDS molecules (10-6) and PC and pentanol. The resulting system can be described as a nanostructured fluid with a huge interfacial area and a small dispersed phase. PMID:16008380
Liquid chromatographic analysis of coal surface properties. Quarterly progress report, April--June 1993
Kwon, K.C.; Rigby, R.
Experiments were performed on equilibrium adsorption of probes (2-methyl-1-pentanol (2M1P), 1-heptanol, benzene, toluene) on 60-200 mesh Illinois 6 coal, Adaville 1 coal, Wyodak coal, and Pittsburgh 8 coal. Equil. loadings of toluene are higher than those of benzene on the 4 coals. The aromatics (tolene, benzene) obey the Langmuir isotherm model for single-layer adsorption up to 100 ppM. Loadings of 2M1P and 1-heptanol do not follow both the Langmuir and the Freundlich empirical model. Flotation of the coals, equilibrated with aq. solns. of 2M1P and 1-heptanol, increase linearly with Equil. loadings. Equil. adsorption loadings of 1-heptanol on Illinois 6 coal increase with decreased adsorption temperature.
Characterisation of optically cleared paper by optical coherence tomography
Fabritius, T; Alarousu, E; Prykaeri, T; Hast, J; Myllylae, Risto [Department of Electrical and Information Engineering, Optoelectronics and Measurement Techniques Laboratory, University of Oulu (Finland)
Due to the highly light scattering nature of paper, the imaging depth of optical methods such as optical coherence tomography (OCT) is limited. In this work, we study the effect of refractive index matching on improving the imaging depth of OCT in paper. To this end, four different refractive index matching liquids (ethanol, 1-pentanol, glycerol and benzyl alcohol) with a refraction index between 1.359 and 1.538 were used in experiments. Low coherent light transmission was studied in commercial copy paper sheets, and the results indicate that benzyl alcohol offers the best improvement in imaging depth, while also being sufficiently stable for the intended purpose. Constructed cross-sectional images demonstrate visually that the imaging depth of OCT is considerably improved by optical clearing. Both surfaces of paper sheets can be detected along with information about the sheet's inner structure. (laser applications and other topics in quantum electronics)
Monte Carlo simulation of optical clearing of paper in optical coherence tomography
Kirillin, M Yu; Priezzhev, A V [Department of Physics, M.V. Lomonosov Moscow State University, Moscow (Russian Federation); Hast, J; Myllylae, Risto [Optoelectronics and Measurements Techniques Laboratory, Faculty of Technology, University of Oulu and Infotech Oulu (Finland)
Signals of an optical coherence tomograph from paper samples are calculated by the Monte Carlo method before and after the action of different immersion liquids such as ethanol, glycerol, benzyl alcohol, and 1-pentanol. It is shown within the framework of the model used that all these liquids reduce the contrast of the inhomogeneity image in upper layers of the samples, considerably improving, however, the visibility of lower layers, allowing the localisation of the rear boundary of a medium being probed, which is important for precision contactless measuring a paper sheet thickness, for example, during the manufacturing process. The results of calculations are in well agreement with experimental data. (laser applications and other topics in quantum electronics)
Optical constants of alcohols in the infrared
NASA Technical Reports Server (NTRS)
Sethna, P. P.; Williams, D.
The spectral reflectances at near-normal incidence for methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol are reported for the spectral range 6700-350 kaysers. The real and imaginary parts of the complex index of refraction of these liquids are obtained in the range 4000-400 kaysers by use of Kramers-Kronig phase-shift analysis. For all of the alcohols studied, the strength for the OH-stretch bands is directly proportional to the number of OH groups per unit volume; similar relations are established for CH- and CO-stretch bands. Absorption cross sections for stretch vibrations of the three groups are considered, and the role of characteristic group intensities in intensity spectroscopy is discussed.
Microbial Oxidation of Gaseous Hydrocarbons: Production of Secondary Alcohols from Corresponding n-Alkanes by Methane-Utilizing Bacteria
Patel, Ramesh N.; Hou, C. T.; Laskin, A. I.; Felix, A.; Derelanko, P.
Over 20 new strains of methane-utilizing bacteria were isolated from lake water and soil samples. Cell suspensions of these and of other known strains of methane-utilizing bacteria oxidized n-alkanes (propane, butane, pentane, hexane) to their corresponding secondary alcohols (2-propanol, 2-butanol, 2-pentanol, 2-hexanol). The product secondary alcohols accumulated extracellularly. The rate of production of secondary alcohols varied with the organism used for oxidation. The average rate of 2-propanol, 2-butanol, 2-pentanol, and 2-hexanol production was 1.5, 1.0, 0.15, and 0.08 ?mol/h per 5.0 mg of protein in cell suspensions, respectively. Secondary alcohols were slowly oxidized further to the corresponding methylketones. Primary alcohols and aldehydes were also detected in low amounts (rate of production were 0.05 to 0.08 ?mol/h per 5.0 mg of protein in cell suspensions) as products of n-alkane (propane and butane) oxidation. However, primary alcohols and aldehydes were rapidly metabolized further by cell suspensions. Methanol-grown cells of methane-utilizing bacteria did not oxidize n-alkanes to their corresponding secondary alcohols, indicating that the enzymatic system required for oxidation of n-alkanes was induced only during growth on methane. The optimal conditions for in vivo secondary alcohol formation from n-alkanes were investigated in Methylosinus sp. (CRL-15). The rate of 2-propanol and 2-butanol production was linear for the 40-min incubation period and increased directly with cell protein concentration up to 12 mg/ml. The optimal temperature and pH for the production of 2-propanol and 2-butanol were 40░C and pH 7.0. Metalchelating agents inhibited the production of secondary alcohols. The activities for the hydroxylation of n-alkanes in various methylotrophic bacteria were localized in the cell-free particulate fractions precipitated by centrifugation between 10,000 and 40,000 ū g. Both oxygen and reduced nicotinamide adenine dinucleotide were required for hydroxylation activity. The metal-chelating agents inhibited hydroxylation of n-alkanes by the particulate fraction, indicating the involvement of a metal-containing enzyme system in the oxidation of n-alkanes. The production of 2-propanol from the corresponding n-alkane by the particulate fraction was inhibited in the presence of methane, suggesting that the subterminal hydroxylation of n-alkanes may be catalyzed by methane monooxygenase. PMID:16345537
Kinetics and products of the reactions of hydroxyl radicals with selected volatile organic compounds, including oxygenated compounds
NASA Astrophysics Data System (ADS)
Bethel, Heidi Lynn
Kinetics, products and reaction mechanisms of the OH radical-initiated reactions of selected volatile organic compounds (VOCs) and oxygenated compounds were examined. These compounds are important smog forming chemicals that are found in gasoline and many consumer products. Smog is created by the interaction of these VOCs with oxides of nitrogen in the presence of sunlight. The hydroxyl (OH) radical is a daytime species and a key initiator of the VOC reactions which lead to photochemical smog formation. Chapter II investigates the OH radical-initiated reactions of p-xylene, 1,2,3-, and 1,2,4-trimethylbenzene which are components of gasoline fuels, vehicle exhaust and ambient air in urban areas. Experiments were conducted at varying NO2 concentrations in indoor environmental chambers in order to determine the dependence of the product yields as a function of NO2 concentrations. From these experiments and previous literature yields, a majority of the products from these reactions under atmospheric conditions have now been elucidated. Chapter III examines the OH radical-initiated reaction of 3-hexene-2,5-dione which is formed from the reactions of p-xylene and 1,2,4-trimethylbenzene (Chapter II). Due to its polar nature, 3-hexene-2,5-dione and its reaction products are difficult to handle experimentally. Products identified from this reaction through the use of in situ atmospheric pressure ionization tandem mass spectrometry were CH3C(O)CH(OH)CHO and CH 3C(O)CH(OH)CH(ONO2)C(O)CH3. Chapters IV, V, and VI examine the OH radical-initiated reactions of 6 different alcohols, including diols. The products examined in Chapters IV and V are those from 2-methyl-2,4-pentanediol and 1,2-, 1,3-, and 2,3-butanediol, which are found in various solvents. Reaction rates were determined using a relative rate method. Hydroxyaldehyde and hydroxyketone products from these reactions were also quantified. Chapter VI examined the reaction rates and products formed from the OH radical-initiated reactions of 2-methyl-2-pentanol and 4-methyl-2-pentanol. These compounds were studied in order to investigate the formation of alkoxy radicals (ROĢ) and their subsequent reactions through isomerization, decomposition or reaction with O2 . Experiments of the type detailed here allow the determination of kinetics and products of the atmospheric reactions of VOCs and provide input for mechanistic models of photochemical smog formation.
Importance of the Debye interaction in organic solutions: Henry's law constants for polar liquids in nonpolar solvents and vice versa
Rytting, J.H.; McHan, D.R.; Higuchi, T.; Grant, D.J.W.
Henry's law constants have been determined for ..gamma..-butyrolactone (BL), ethyl acetate (EA), and 2-methyl-3-pentanol (MEP) in mixtures of iso-octane (ISO) and toluene (TOL), for BL, EA, TOL, and ISO in cinnamaldehyde (CIN) and for TOL and ISO in each other and in BL. From these data and published vapor pressures, the activity coefficients at infinite dilution and the standard molar Gibbs free energy of transfer, ..delta..G/sub 2/..pi.. of the solutes from dilute solution in ISO to dilute solution in each solvent medium have been calculated. The different behavior patterns of BL and EA are attributed to differences in their abilities to exist in different conformations possessing different dipole moments. For polar solutes, ..delta..G/sub 2//sup 0/ decreases with increasing polarizability of the solvent and with increasing dipole moment of the solute, suggesting increased contributions from dipole-induced dipole (Debye) interactions. The sigmoidal plot of ..delta..G/sub 2//sup 0/ against the change in pair potential energy calculated from the classical expressions suggests that ..delta..G/sub 2//sup 0/ seriously underestimates the strength of the Debye interactions in comparison with the London interactions.
Two Volatile Organic Compounds Trigger Plant Self-Defense against a Bacterial Pathogen and a Sucking Insect in Cucumber under Open Field Conditions.
Song, Geun Cheol; Ryu, Choong-Min
Systemic acquired resistance (SAR) is a plant self-defense mechanism against a broad-range of pathogens and insect pests. Among chemical SAR triggers, plant and bacterial volatiles are promising candidates for use in pest management, as these volatiles are highly effective, inexpensive, and can be employed at relatively low concentrations compared with agrochemicals. However, such volatiles have some drawbacks, including the high evaporation rate of these compounds after application in the open field, their negative effects on plant growth, and their inconsistent levels of effectiveness. Here, we demonstrate the effectiveness of volatile organic compound (VOC)-mediated induced resistance against both the bacterial angular leaf spot pathogen, Pseudononas syringae pv. lachrymans, and the sucking insect aphid, Myzus persicae, in the open field. Using the VOCs 3-pentanol and 2-butanone where fruit yields increased gave unexpectedly, a significant increase in the number of ladybird beetles, Coccinella septempunctata, a natural enemy of aphids. The defense-related gene CsLOX was induced by VOC treatment, indicating that triggering the oxylipin pathway in response to the emission of green leaf volatiles can recruit the natural enemy of aphids. These results demonstrate that VOCs may help prevent plant disease and insect damage by eliciting induced resistance, even in open fields. PMID:23698768
Two Volatile Organic Compounds Trigger Plant Self-Defense against a Bacterial Pathogen and a Sucking Insect in Cucumber under Open Field Conditions
Song, Geun Cheol; Ryu, Choong-Min
Systemic acquired resistance (SAR) is a plant self-defense mechanism against a broad-range of pathogens and insect pests. Among chemical SAR triggers, plant and bacterial volatiles are promising candidates for use in pest management, as these volatiles are highly effective, inexpensive, and can be employed at relatively low concentrations compared with agrochemicals. However, such volatiles have some drawbacks, including the high evaporation rate of these compounds after application in the open field, their negative effects on plant growth, and their inconsistent levels of effectiveness. Here, we demonstrate the effectiveness of volatile organic compound (VOC)-mediated induced resistance against both the bacterial angular leaf spot pathogen, Pseudononas syringae pv. lachrymans, and the sucking insect aphid, Myzus persicae, in the open field. Using the VOCs 3-pentanol and 2-butanone where fruit yields increased gave unexpectedly, a significant increase in the number of ladybird beetles, Coccinella septempunctata, a natural enemy of aphids. The defense-related gene CsLOX was induced by VOC treatment, indicating that triggering the oxylipin pathway in response to the emission of green leaf volatiles can recruit the natural enemy of aphids. These results demonstrate that VOCs may help prevent plant disease and insect damage by eliciting induced resistance, even in open fields. PMID:23698768
Aroma enhancement and enzymolysis regulation of grape wine using ?-glycosidase.
Zhu, Feng-Mei; Du, Bin; Li, Jun
Adding ?-glycosidase into grape wine for enhancing aroma was investigated using gas chromatography-mass spectrometry (GC-MS) and Kramer sensory evaluation. Compared with the extract from control wines, the extract from enzyme-treated wines increased more aromatic compounds using steam distillation extraction (SDE) and GC-MS analyses. Theses aromatic compounds were as follows: 3-methyl-1-butanol formate, 3-pentanol, furfural, 3-methyl-butanoic acid, 2-methyl-butanoic acid, 3-hydroxy-butanoic acid ethyl ester, hexanoic acid, hexanoic acid ethyl ester, benzyl alcohol, octanoic acid, octanoic acid ethyl ester, dodecanoic acid, and ethyl ester. The enzymolysis regulation conditions, including enzymolysis temperature, enzymolysis time, and enzyme amount, were optimized through L9(3(4)) orthogonal test. Kramer sensory evaluation was performed by an 11-man panel of judges. The optimum enzymolysis regulation conditions were found to be temperature of 45░C, enzymolysis time of 90Āmin, and enzyme amount of 58.32ĀU/mL grape wine, respectively. The Kramer sensory evaluation supported that the enzyme-treated wines produced a stronger fragrance. PMID:24804072
Simultaneous convective heat and mass transfer in impingement ink drying
Can, M. [Univ. of Uldag, Bursa (Turkey)] [Univ. of Uldag, Bursa (Turkey)
Effective and economical drying of thin ink films is essential in the printing, packaging and coating industries. In evaporative drying, high heat and mass transfer rates are commonly achieved by means of high velocity impinging air jets. To provide data for dryer design a program of research has been implemented to study the heat and mass transfer processes which underlie the drying of thin ink films. The heat transfer situation under impinging air jets is outlined and some experimental results are presented. Optimization of nozzle arrays for impinging air jets is analyzed for practical applications. A non-contact infra-red technique for continuously monitoring the ink drying process is described and drying curves for an ink based on a single solvent (4-Methyl-2-pentanol-MIBC) are presented. Heat and mass transfer theory has been used to predict drying times in the constant rate drying period. These predictions have been compared with experimentally determined drying times. This research has served to confirm the fundamental importance of the drying curve as a basis for dryer design.
Implementation of multivariate techniques for the selection of volatile compounds as indicators of sensory quality of raw beef.
Saraiva, Cristina; Oliveira, I; Silva, J A; Martins, C; Ventanas, J; GarcĒa, C
This study was performed in order to select volatile compounds to predict the off-odour and overall assessment of raw beef's freshness Maronesa breed, using multivariate analysis. M. longissimus dorsi packed in vacuum and MAP (70Ā% O2/20Ā% CO2/10Ā%ĀN2) stored at 4?║C were examined for off-odour perception as well as the overall assessment of freshness at 10 and 21Ādays post mortem. The results achieved in this study demonstrated that the selected volatile compounds could be considered as volatile indicators of beef spoilage, enclosing information for discrimination of Maronesa beef samples in sensory classes of odour corresponding to unspoiled and spoiled levels. Fifty-four volatile compounds were detected. A significant increase of aldehydes, ketones and alcohols were observed during storage in MAP. 2 and 3-methylbutanal, 2 and 3-methylbutanol, 1-pentanol, 1-hexanol, 2,3-octanedione, 3,5-octanedione, octanal and nonanal were suggested as indicators of beef spoilage. 3-methylpentane was considered as a marker in the first stages of spoilage in beef, decreasing during storage. Data were examined using PCR and PLSR models for different optimal subsets of volatile compounds. The simplicity and usefulness of the technique in using 0/1 data in preserving high levels of accuracy was also prevalent. The powerful analytical methodologies for reducing variables and the choice of optimal subsets could be advantageous in both basic research and the routine quality control of chilled beef. PMID:26028774
Volatile Compounds Originating from Mixed Microbial Cultures on Building Materials under Various Humidity Conditions
Korpi, Anne; Pasanen, Anna-Liisa; Pasanen, Pertti
We examined growth of mixed microbial cultures (13 fungal species and one actinomycete species) and production of volatile compounds (VOCs) in typical building materials in outside walls, separating walls, and bathroom floors at various relative humidities (RHs) of air. Air samples from incubation chambers were adsorbed on Tenax TA and dinitrophenylhydrazine cartridges and were analyzed by thermal desorption-gas chromatography and high-performance liquid chromatography, respectively. Metabolic activity was measured by determining CO2 production, and microbial concentrations were determined by a dilution plate method. At 80 to 82% RH, CO2 production did not indicate that microbial activity occurred, and only 10% of the spores germinated, while slight increases in the concentrations of some VOCs were detected. All of the parameters showed that microbial activity occurred at 90 to 99% RH. The microbiological analyses revealed weak microbial growth even under drying conditions (32 to 33% RH). The main VOCs produced on the building materials studied were 3-methyl-1-butanol, 1-pentanol, 1-hexanol, and 1-octen-3-ol. In some cases fungal growth decreased aldehyde emissions. We found that various VOCs accompany microbial activity but that no single VOC is a reliable indicator of biocontamination in building materials. PMID:9687450
Use of micellar liquid chromatography to analyze darunavir, ritonavir, emtricitabine, and tenofovir in plasma.
Peris-Vicente, Juan; Villarreal-Traver, M¾nica; Casas-Breva, Inmaculada; Carda-Broch, Samuel; Esteve-Romero, Josep
Danuravir, ritonavir, emtricitabine, and tenofovir are together prescribed against AIDS as a highly active antiretroviral therapy regimen. Micellar liquid chromatography has been applied to determine these four antiretroviral drugs in plasma. The sample preparation is shortened to the dilution of the sample in a micellar solution, filtration, and injection. Clean-up steps are avoided, due to the solubilization of plasma matrix in micellar media. The drugs were analyzed in <20Āmin using a mobile phase of 0.06ĀM sodium dodecyl sulfate/2.5% 1-pentanol (pH 7) running under isocratic mode through a C18 column at 1ĀmL/min at room temperature. Absorbance wavelength detection was set at 214Ānm. The method was successfully validated following the ICH Harmonized Tripartite Guideline in terms of selectivity, limit of detection (0.080-0.110 ?g/mL), limit of quantification (0.240-0.270Ā?g/mL), linearity between 0.25 and 25Ā?g/mL (r(2) > 0.995), accuracy (89.3-103.2%), precision (<8.2%) and robustness (<7.5%). Real plasma sample from patients taking this therapy were analyzed. This is the first paper showing the simultaneous detection of this four drugs. Therefore, the methodology was proven useful for the routine analysis of these samples in a hospital laboratory for clinical purposes. PMID:25103282
Density gradient theory combined with the PC-SAFT equation of state used for modeling the surface tension of associating systems
NASA Astrophysics Data System (ADS)
VinÜ, Vßclav; Plankovß, Barbora; Hrub², Jan; Celn², David
The density gradient theory (GT) combined with a SAFT-type (Statistical Associating Fluid Theory) equation of state has been used for modeling the surface tension of associating fluids represented by a series of six alkanols ranging from methanol to 1-pentanol. The effect of nonzero dipole moment of the selected alkanols on the predicted surface tension was investigated in this study. Results of the GT + non-polar Perturbed Chain (PC) SAFT equation of state were compared to predictions of GT combined with the PC-polar-SAFT, i.e. PCP-SAFT, equation. Both GT + PC-SAFT and GT + PCP-SAFT give reasonable prediction of the surface tension for pure alkanols. Results of both models are comparable as no significant difference in the modeled saturation properties and in the predicted surface tension using GT was found. Consideration of dipolar molecules of selected alkanols using PCP-SAFT had only minor effect on the predicted properties compared to the non-polar PC-SAFT model.
Fractionation and identification of minor and aroma-active constituents in Kangra orthodox black tea.
Joshi, Robin; Gulati, Ashu
The aroma constituents of Kangra orthodox black tea were isolated by simultaneous distillation extraction (SDE), supercritical fluid extraction and beverage method. The aroma-active compounds were identified using gas chromatography-olfactometry-mass spectrometry. Geraniol, linalool, (Z/E)-linalool oxides, (E)-2-hexenal, phytol, ?-ionone, hotrienol, methylpyrazine and methyl salicylate were major volatile constituents in all the extracts. Minor volatile compounds in all the extracts were 2-ethyl-5-methylpyrazine, ethylpyrazine, 2-6,10,14-trimethyl-2-pentadecanone, acetylfuran, hexanoic acid, dihydroactinidiolide and (E/Z)-2,6-nonadienal. The concentrated SDE extract was fractionated into acidic, basic, water-soluble and neutral fractions. The neutral fraction was further chromatographed on a packed silica gel column eluted with pentane and diethyl ether to separate minor compounds. The aroma-active compounds identified using gas chromatography-olfactometry-mass spectrometry were 2-amylfuran, (E/Z)-2,6-nonadienal, 1-pentanol, epoxylinalool, (Z)-jasmone, 2-acetylpyrrole, farnesyl acetone, geranyl acetone, cadinol, cubenol and dihydroactinidiolide. AEDA studies showed 2-hexenal, 3-hexenol, ethylpyrazine, (Z/E)-linalool oxides, linalool, (E/Z)-2,6-nonadienal, geraniol, phenylethanol, ?-ionone, hotrienol and dihydroactinidiolide to be odour active components. PMID:25148991
Occurrence and behavior of system peaks in RP HPLC with solely aqueous mobile phases.
KalĒkovß, Kveta; Hruska, Vlastimil; Svobodovß, Jana; Chudoba, Richard; Gas, Bohuslav; Tesarovß, Eva
System peaks are important but often also disturbing phenomena occurring in separation systems. Behavior of system peaks was studied in reversed phase high performance liquid chromatography (RP HPLC) systems consisting of an RP Amide C16 column and aqueous solutions of organic acids with alkaline metal hydroxides as mobile phases. Binary mobile phases, composed of benzoic acid and lithium hydroxide (LiOH) or cesium hydroxide (CsOH), yielded two system peaks. The first peak was stationary and the second one moved with dilution of the mobile phase or with changes of the alkaline metal hydroxide concentration. The latter changes affected dissociation of the benzoic acid present in the mobile phase and thereby its retention. The presumption that the first system peak is not influenced by the type of alkaline metal cation and that it is related to the non-adsorbed component of the mobile phase was confirmed by a cyclic procedure. Three-component mobile phases composed of benzoic acid, tropic acid, and a hydroxide gave rise to three system peaks as expected. The first peak was again stationary and the two others shifted depending on the concentration variation of both acids. Resonance causing a zigzag peak, well described in capillary zone electrophoresis (CZE), was observed if 1-pentanol was injected into a chromatographic system with one-component mobile phase. PMID:19639550
Male and female noctuid moths attracted to synthetic lures in Europe.
T¾th, Mikl¾s; Szarukßn, Istvßn; Dorogi, Bķla; Gulyßs, Attila; Nagy, Pßl; Rozgonyi, Zoltßn
In field tests in Europe, traps baited with a blend of isoamyl alcohol, acetic acid, and isobutanol (compounds previously found attractive to a number of noctuids in North America) caught the following noctuid moths: Agrotis segetum Schiff., Agrotis crassa Hbn., Agrotis exclamationis L., Amathes (Xestia) c-nigrum L., Apatele rumicis L., Amphipyra pyramidea L., Dipterygia scabriuscula L., Discestra trifolii Hfn., Euxoa aquilina Schiff., Euclidia glyphica L., Mamestra brassicae L., Mamestra oleracea L., Mamestra suasa Schiff., Mythimna albipuncta Den. & Schiff., Mythimna l-album L., Noctua pronuba L., and Trachea atriplicis L. A substantial percentage of the catch of each species of moths was females. The presence of isobutanol in the mixture was important for catching A. rumicis, D. trifolii, and E. glyphica. The addition of 3-methyl-1-pentanol to the ternary mixture did not increase trap captures of any of the moths. Traps baited with the floral attractant phenylacetaldehyde alone caught several species of noctuid moths. However, when phenylacetaldehyde was added to the isoamyl-alcohol ternary blend, no increases in catches of any of the species, relative to the ternary blend or phenyacetaldehyde alone, were observed, with catches of most species being depressed. Comparing the noctuid species attracted to the phenylacetaldehyde- and isoamyl alcohol-based lures showed that phenylacetaldehyde attracted predominantly Plusiinae and Melicleptriinae spp., while isoamyl alcohol-based lures attracted species mostly from the Noctuinae or Hadeninae subfamilies. PMID:20449640
Synthesis of 2,3,9,10,16,17,23,24-Octaalkynylphthalocyanines and the Effects of Concentration and Temperature on Their (1)H NMR Spectra.
Terekhov, Dmitri S.; Nolan, Kieran J. M.; McArthur, Colin R.; Leznoff, Clifford C.
The syntheses of 3,4- and 4,5-diiodophthalonitriles are described. Coupling of the latter compound with Pd(PPh(3))(2)Cl(2) and 1-octyne, 1-heptyne, 1-hexyne, 1-pentyne, and 3,3-dimethyl-1-butyne gave a series of 4,5-dialkynylphthalonitriles. Hydrogenation of 4,5-bis(1-pentynyl)phthalonitrile and 4,5-bis(3,3-dimethyl-1-butynyl)phthalonitrile gave 4,5-dipentylphthalonitrile and 4,5-bis(3,3-dimethylbutyl)phthalonitriles. Condensation of the dialkynylphthalonitriles with lithium 1-pentoxide in 1-pentanol gave 2,3,9,10,16,17,23,24-octaalkynylphthalocyanines, while intervention of the intermediate dilithium phthalocyanines with zinc acetate gave the related zinc(II) phthalocyanines. (1)H NMR spectroscopy of these octaalkynylphthalocyanines exhibited large chemical shifts (1-2 ppm) of the internal and aromatic protons at concentrations ranging from 10(-)(2) to 10(-)(5) M and at temperatures from 27 to 147 degrees C. The effects of aggregation phenomena are discussed. The importance of reporting concentration and temperature values for NMR spectra of phthalocyanines is stressed. PMID:11667165
Anticancer Properties of Novel Rhenium Pentylcarbanato Compounds against MDA-MB-468(HTB-132) Triple Node Negative Human Breast Cancer Cell Lines
Parson, Carl; Smith, Valerie; Krauss, Christopher; Banerjee, Hirendra N.; Reilly, Christopher; Krause, Jeanette A.; Wachira, James M.; Giri, Dipak; Winstead, Angela; Mandal, Santosh K.
Aim To study the efficacy of novel rhenium compounds to treat triple node negative breast cancer. Place and Duration Six (6) novel rhenium pentycarbanato compounds (PC1-6) were synthesized and triple node negative breast cancer cell lines HTB-132 and Balb/c mouse kidney cell lines were treated with each of them for 48 hours. The results were analyzed by a common trypan blue cell death assay system and statistically analyzed. Place and Duration The compounds were synthesized, analyzed and evaluated at the Department of Chemistryof Morgan State University, Baltimore, Maryland and the Pharmaceutical Sciences Department of Elizabeth City State University campus of the University of North Carolina system. Methodology The novel rhenium compounds were synthesized from one-pot reactions of Re2(CO)10 with the corresponding ?-diimine ligands in 1-pentanol.The compounds were characterized spectroscopically. The cell lines were cultured by standard cell culture procedure and treated with each of the six compounds in DMSO for 48 hours with a negative control and a DMSO vehicular control along with a cisplatin positive control.The cytotoxicity was evaluated by standard trypan blue assay and the results were statistically analyzed. Results The trypan blueassay reveals that these compounds have significant cytotoxicity against MDA-MB-468 (HTB-132) triple node negative breast cancer cell lines and are less nephrotoxic than cisplatin. Conclusion The novel rhenium compounds PC 1-6 can potentially find applications in the treatment of highly malignant triple node negative breast cancer. PMID:25419517
Improvement of the Dimensional Stability of Powder Injection Molded Compacts by Adding Swelling Inhibitor into the Debinding Solvent
NASA Astrophysics Data System (ADS)
Fan, Yang-Liang; Hwang, Kuen-Shyang; Su, Shao-Chin
Defects are frequently found in powder injection molded (PIM) compacts during solvent debinding due to the swelling of the binders. This problem can be alleviated by adjusting the composition of the debinding solvent. In this study, 10 vol pct swelling inhibitors were added into heptane, and the in-situ amounts of swelling and sagging of the specimen in the solvent were recorded using a noncontacting laser dilatometer. The results show that the addition of ethanol, 2-propanol, 1-butanol, and 1-pentanol reduced the amounts of swelling by 31, 21, 17, and 11 pct, respectively. This was because the small molecule alcohols, which do not dissolve paraffin wax (PW) or stearic acid (SA) in the binder system, could diffuse easily into the specimen and increased the portion of the swelling inhibitor inside. The amount of the extracted PW and SA also decreased, but only by 8.3, 6.1, 4.3, and 2.4 pct, respectively. The solubility parameters of 1-bromopropane (n-PB) and ethyl acetate (EA) are between those of heptane and alcohols, and they also yielded a slight reduction in the amounts of swelling by 6 and 11 pct, respectively. These results suggest that to reduce defects caused by binder swelling during solvent debinding, alcohols with high solubility parameters can be added into heptane without sacrificing significantly on the debinding rate.
Analysis of volatile compounds and triglycerides of seed oils extracted from different poppy varieties (Papaver somniferum L.).
Krist, Sabine; Stuebiger, Gerald; Unterweger, Heidrun; Bandion, Franz; Buchbauer, Gerhard
Poppy seed oil (Oleum Papaveris Seminis) is used for culinary and pharmaceutical purposes, as well as for making soaps, paints, and varnishes. Astonishingly, hardly anything was yet known about the volatile compounds of this promising comestible. Likewise, there are no current published data about the triglyceride (TAG) composition of poppy seed oils available. In this investigation solid-phase microextraction (SPME) with DVB/Carboxen/PDMS Stable-Flex fiber was applied to the study of volatile compounds of several seed oil samples from Papaver somniferum L. (Papaveraceae). 1-Pentanol (3.3-4.9%), 1-hexanal (10.9-30.9%), 1-hexanol (5.3-33.7%), 2-pentylfuran (7.2-10.0%), and caproic acid (2.9-11.5%) could be identified as the main volatile compounds in all examined poppy seed oil samples. Furthermore, the TAG composition of these oils was analyzed by MALDI-ReTOF- and ESI-IT-MS/MS. The predominant TAG components were found to be composed of linoleic, oleic, and palmitic acid, comprising approximately 70% of the oils. TAG patterns of the different poppy varieties were found to be very homogeneous, showing also no significant differences in terms of the applied pressing method of the plant seeds. PMID:16218681
Determination of paroxetine in blood and urine using micellar liquid chromatography with electrochemical detection.
Agrawal, Nitasha; Marco-Peir¾, Sergio; Esteve-Romero, Josep; Durgbanshi, Abhilasha; Bose, Devasish; Peris-Vicente, Juan; Carda-Broch, Samuel
Paroxetine is a potent selective serotonin reuptake inhibitor used for the treatment of depression and related mood disorders. A micellar liquid chromatographic method was developed for the determination of paroxetine in serum and urine. Detection of paroxetine was carried out using a C18 column and a mobile phase of 0.15 M sodium dodecyl sulfate, 6% 1-pentanol at pH 3 (buffer salt 0.01 M NaH2PO4) running under isocratic mode at 1.0 mL/min and electrochemical detection at 0.8 V. The analyte was eluted without interferences in <15 min. The proposed methodology was validated under the guidelines of the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use in matrix in terms of specificity, linearity (r(2) > 0.9999; 0.5-5 ?g/mL range), accuracy (88-97.5%, recovery), repeatability (RSD < 0.54%), intermediate precision (RSD < 0.54%), limit of detection and quantification (0.001 and 0.005 ?g/mL, respectively) and robustness (RSD < 3.63%). Developed method was successfully applied to real blood and urine samples as well as in spiked serum and urine samples. The developed method was specific, rapid, precise, reliable, accurate, inexpensive and then suitable for routine analysis of paroxetine in monitorized samples. PMID:24448669
Contribution of liver alcohol dehydrogenase to metabolism of alcohols in rats.
Plapp, Bryce V; Leidal, Kevin G; Murch, Bruce P; Green, David W
The kinetics of oxidation of various alcohols by purified rat liver alcohol dehydrogenase (ADH) were compared with the kinetics of elimination of the alcohols in rats in order to investigate the roles of ADH and other factors that contribute to the rates of metabolism of alcohols. Primary alcohols (ethanol, 1-propanol, 1-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol) and diols (1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol) were eliminated in rats with zero-order kinetics at doses of 5-20mmol/kg. Ethanol was eliminated most rapidly, at 7.9mmol/kgh. Secondary alcohols (2-propanol-d7, 2-propanol, 2-butanol, 3-pentanol, cyclopentanol, cyclohexanol) were eliminated with first order kinetics at doses of 5-10mmol/kg, and the corresponding ketones were formed and slowly eliminated with zero or first order kinetics. The rates of elimination of various alcohols were inhibited on average 73% (55% for 2-propanol to 90% for ethanol) by 1mmol/kg of 4-methylpyrazole, a good inhibitor of ADH, indicating a major role for ADH in the metabolism of the alcohols. The Michaelis kinetic constants from in vitro studies (pH 7.3, 37░C) with isolated rat liver enzyme were used to calculate the expected relative rates of metabolism in rats. The rates of elimination generally increased with increased activity of ADH, but a maximum rate of 6▒1mmol/kgh was observed for the best substrates, suggesting that ADH activity is not solely rate-limiting. Because secondary alcohols only require one NAD(+) for the conversion to ketones whereas primary alcohols require two equivalents of NAD(+) for oxidation to the carboxylic acids, it appears that the rate of oxidation of NADH to NAD(+) is not a major limiting factor for metabolism of these alcohols, but the rate-limiting factors are yet to be identified. PMID:25641189
Can Volatile Organic Metabolites Be Used to Simultaneously Assess Microbial and Mite Contamination Level in Cereal Grains and Coffee Beans?
Salvador, ┬ngelo C.; Baptista, InĻs; Barros, Ant¾nio S.; Gomes, Newton C. M.; Cunha, ┬ngela; Almeida, Adelaide; Rocha, Silvia M.
A novel approach based on headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography¢time-of-flight mass spectrometry (GCūGC¢ToFMS) was developed for the simultaneous screening of microbial and mite contamination level in cereals and coffee beans. The proposed approach emerges as a powerful tool for the rapid assessment of the microbial contamination level (ca. 70 min versus ca. 72 to 120 h for bacteria and fungi, respectively, using conventional plate counts), and mite contamination (ca. 70 min versus ca. 24 h). A full-factorial design was performed for optimization of the SPME experimental parameters. The methodology was applied to three types of rice (rough, brown, and white rice), oat, wheat, and green and roasted coffee beans. Simultaneously, microbiological analysis of the samples (total aerobic microorganisms, moulds, and yeasts) was performed by conventional plate counts. A set of 54 volatile markers was selected among all the compounds detected by GCūGC¢ToFMS. Principal Component Analysis (PCA) was applied in order to establish a relationship between potential volatile markers and the level of microbial contamination. Methylbenzene, 3-octanone, 2-nonanone, 2-methyl-3-pentanol, 1-octen-3-ol, and 2-hexanone were associated to samples with higher microbial contamination level, especially in rough rice. Moreover, oat exhibited a high GC peak area of 2-hydroxy-6-methylbenzaldehyde, a sexual and alarm pheromone for adult mites, which in the other matrices appeared as a trace component. The number of mites detected in oat grains was correlated to the GC peak area of the pheromone. The HS-SPME/GCūGC¢ToFMS methodology can be regarded as the basis for the development of a rapid and versatile method that can be applied in industry to the simultaneous assessment the level of microbiological contamination and for detection of mites in cereals grains and coffee beans. PMID:23613710
Purification and Properties of Primary and Secondary Alcohol Dehydrogenases from Thermoanaerobacter ethanolicus
Bryant, Frank O.; Wiegel, Juergen; Ljungdahl, Lars G.
Thermoanaerobacter ethanolicus (ATCC 31550) has primary and secondary alcohol dehydrogenases. The two enzymes were purified to homogeneity as judged from sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration. The apparent Mrs of the primary and secondary alcohol dehydrogenases are 184,000 and 172,000, respectively. Both enzymes have high thermostability. They are tetrameric with apparently identical subunits and contain from 3.2 to 5.5 atoms of Zn per subunit. The two dehydrogenases are NADP dependent and reversibly convert ethanol and 1-propanol to the respective aldehydes. The Vm values with ethanol as a substrate are 45.6 ?mol/min per mg for the primary alcohol dehydrogenase and 13 ?mol/min per mg for the secondary alcohol dehydrogenase at pH 8.9 and 60░C. The primary enzyme oxidizes primary alcohols, including up to heptanol, at rates similar to that of ethanol. It is inactive with secondary alcohols. The secondary enzyme is inactive with 1-pentanol or longer chain alcohols. Its best substrate is 2-propanol, which is oxidized 15 times faster than ethanol. The secondary alcohol dehydrogenase is formed early during the growth cycle. It is stimulated by pyruvate and has a low Km for acetaldehyde (44.8 mM) in comparison to that of the primary alcohol dehydrogenase (210 mM). The latter enzyme is formed late in the growth cycle. It is postulated that the secondary alcohol dehydrogenase is largely responsible for the formation of ethanol in fermentations of carbohydrates by T. ethanolicus. Images PMID:16347559
Exhalation pattern changes during fasting and low dose glucose treatment in rats.
Fink, Tobias; Albrecht, Frederic W; Maurer, Felix; Kleber, Astrid; H³ppe, Tobias; Schnauber, Kristina; Wolf, Beate; Baumbach, J÷rg I; Volk, Thomas; Kreuer, Sascha
The analysis of exhaled metabolites has become a promising field of research in recent decades. Several volatile organic compounds reflecting metabolic disturbance and nutrition status have even been reported. These are particularly important for long-term measurements, as needed in medical research for detection of disease progression and therapeutic efficacy. In this context, it has become urgent to investigate the effect of fasting and glucose treatment for breath analysis. In the present study, we used a model of ventilated rats that fasted for 12Āh prior to the experiment. Ten rats per group were randomly assigned for continuous intravenous infusion without glucose or an infusion including 25Āmg glucose per 100Āg per hour during an observation period of 12Āh. Exhaled gas was analysed using multicapillary column ion-mobility spectrometry. Analytes were identified by the BS-MCC/IMS database (version 1209; B & S Analytik, Dortmund, Germany). Glucose infusion led to a significant increase in blood glucose levels (p?0.05 at 4Āh and thereafter) and cardiac output (p?0.05 at 4Āh and thereafter). During the observation period, 39 peaks were found collectively. There were significant differences between groups in the concentration of ten volatile organic compounds: p?0.001 at 4Āh and thereafter for isoprene, cyclohexanone, acetone, p-cymol, 2-hexanone, phenylacetylene, and one unknown compound, and p?0.001 at 8Āh and thereafter for 1-pentanol, 1-propanol, and 2-heptanol. Our results indicate that for long-term measurement, fasting and the withholding of glucose could contribute to changes of volatile metabolites in exhaled air. PMID:25808025
Isoform Selectivity of Adenylyl Cyclase Inhibitors: Characterization of Known and Novel Compounds
Brand, Cameron S.; Hocker, Harrison J.; Gorfe, Alemayehu A.; Cavasotto, Claudio N.
Nine membrane-bound adenylyl cyclase (AC) isoforms catalyze the production of the second messenger cyclic AMP (cAMP) in response to various stimuli. Reduction of AC activity has well documented benefits, including benefits for heart disease and pain. These roles have inspired development of isoform-selective AC inhibitors, a lack of which currently limits exploration of functions and/or treatment of dysfunctions involving AC/cAMP signaling. However, inhibitors described as AC5- or AC1-selective have not been screened against the full panel of AC isoforms. We have measured pharmacological inhibitor profiles for all transmembrane AC isoforms. We found that 9-(tetrahydro-2-furanyl)-9H-purin-6-amine (SQ22,536), 2-amino-7-(furanyl)-7,8-dihydro-5(6H)-quinazolinone (NKY80), and adenine 9-?-d-arabinofuranoside (Ara-A), described as supposedly AC5-selective, do not discriminate between AC5 and AC6, whereas the putative AC1-selective inhibitor 5-?[[2-?(6-?amino-?9H-?purin-?9-?yl)?ethyl]?amino]?-?1-?pentanol (NB001) does not directly target AC1 to reduce cAMP levels. A structure-based virtual screen targeting the ATP binding site of AC was used to identify novel chemical structures that show some preference for AC1 or AC2. Mutation of the AC2 forskolin binding pocket does not interfere with inhibition by SQ22,536 or the novel AC2 inhibitor, suggesting binding to the catalytic site. Thus, we show that compounds lacking the adenine chemical signature and targeting the ATP binding site can potentially be used to develop AC isoform¢specific inhibitors, and discuss the need to reinterpret literature using AC5/6-selective molecules SQ22,536, NKY80, and Ara-A. PMID:24006339
Gas-phase reactivity of protonated 2-, 3-, and 4-dehydropyridine radicals toward organic reagents.
Adeuya, Anthony; Price, Jason M; Jankiewicz, Bart?omiej J; Nash, John J; Kenttõmaa, Hilkka I
To explore the effects of the electronic nature of charged phenyl radicals on their reactivity, reactions of the three distonic isomers of n-dehydropyridinium cation (n = 2, 3, or 4) have been investigated in the gas phase by using Fourier-transform ion cyclotron resonance mass spectrometry. All three isomers react with cyclohexane, methanol, ethanol, and 1-pentanol exclusively via hydrogen atom abstraction and with allyl iodide mainly via iodine atom abstraction, with a reaction efficiency ordering of 2 > 3 > 4. The observed reactivity ordering correlates well with the calculated vertical electron affinities of the charged radicals (i.e., the higher the vertical electron affinity, the faster the reaction). Charged radicals 2 and 3 also react with tetrahydrofuran exclusively via hydrogen atom abstraction, but the reaction of 4 with tetrahydrofuran yields products arising from nonradical reactivity. The unusual reactivity of 4 is likely to result from the contribution of an ionized carbene-type resonance structure that facilitates nucleophilic addition to the most electrophilic carbon atom (C-4) in this charged radical. The influence of such a resonance structure on the reactivity of 2 is not obvious, and this may be due to stabilizing hydrogen-bonding interactions in the transition states for this molecule. Charged radicals 2 and 3 abstract a hydrogen atom from the substituent in both phenol and toluene, but 4 abstracts a hydrogen atom from the phenyl ring, a reaction that is unprecedented for phenyl radicals. Charged radical 4 reacts with tert-butyl isocyanide mainly by hydrogen cyanide (HCN) abstraction, whereas CN abstraction is the principal reaction for 2 and 3. The different reactivity observed for 4 (as compared to 2 and 3) is likely to result from different charge and spin distributions of the reaction intermediates for these charged radicals. PMID:19902945
Analysis of thiabendazole, 4-tert-octylphenol and chlorpyrifos in waste and sewage water by direct injection ¢ micellar liquid chromatography.
Romero-Cano, Ricard; Kassuha, Diego; Peris-Vicente, Juan; Roca-Genovķs, Pasqual; Carda-Broch, Samuel; Esteve-Romero, Josep
A micellar liquid chromatographic method has been developed for the simultaneous quantification of the pesticides thiabendazole and chlorpyrifos, as well as an alkylphenol, which is included in pesticide formulations, i.e., 4-tert-octylphenol, in water. A sample was filtered and directly injected, avoiding large extraction steps using toxic solvents, thus expediting the experimental procedure. The contaminants were eluted without interferences in <17 min, using a mobile phase of 0.15 M sodium dodecyl sulfate ¢ 6% 1-pentanol buffered at pH 3, running through a C18 column at 1 mL min(-1) under the isocratic mode. This optimal mobile phase was selected using a statistical approach, which considers the retention factor, efficiency and peak shape of the analytes measured in only a few mobile phases. The detection was carried out by measuring absorbance at 220 nm. The method was successfully validated in terms of specificity, calibration range (0.5-10 mg L(-1)), linearity (r(2) > 0.994), limit of detection and quantification (0.2-0.3; and 0.5-0.8 mg L(-1), respectively), intra- and interday accuracy (95.2-102.9%), precision (<8.3%), and ruggedness (<9.3%). The stability in storage conditions (at least 14 days) was studied. The method was safe, inexpensive, produced little pollutant and has a short analysis time, thus it is useful for the routine analysis of samples. Finally, the method was applied to analyse wastewater from the fruit-processing industry, wastewater treatment plants, and in sewage water belonging to the Castell¾ area (Spain). The results were similar to those obtained by an already reliable method. PMID:25604004
Physicochemical studies of mixed surfactant microemulsions with isopropyl myristate as oil.
Bardhan, Soumik; Kundu, Kaushik; Saha, Swapan K; Paul, Bidyut K
The present study is focused on evaluation of interfacial compositions and thermodynamic properties of w/o mixed surfactant [(sodium dodecylsulfate, SDS/polyoxyethylene (23) lauryl ether, Brij-35)/1-pentanol (Pn)/isopropyl myristate (IPM)] microemulsions under various physicochemical conditions by the dilution method. The number of moles of Pn at the interface (n(a)(i)) and bulk oil (n(a)(o)), and various thermodynamic parameters [viz. standard Gibbs free energy (?G(o?i)(0)), standard enthalpy (?H(o?i)(0)), and standard entropy (?S(o?i)(0)) of the transfer of Pn from bulk oil to the interface] have been found to be dependent on the molar ratio of water to surfactant (?), concentration of Brij-35 (X(Brij-35)), and temperature. Temperature-insensitive microemulsions with zero specific heat capacity (?C(p)(0))(o?i) have been formed at specific compositions. The intrinsic enthalpy change of the transfer process (?H(0))(o?i)* has been evaluated from linear correlation between ?H(o?i)(0) and ?S(o?i)(0) at different experimental temperatures. The present report also aims at a precise characterization on the basis of molecular interactions between the constituents and provides insight into the nature of the oil/water interfaces of these systems by conductivity and dynamic light scattering studies as a function of ? and X(Brij-35). Conductivity studies reveal that incorporation of Brij-35 in non-percolating water/SDS/Pn/IPM systems makes them favorable for ?-induced percolation behavior up to X(Brij-35) ? 0.5. But further addition of Brij-35 causes a decrease in conductivity with increasing ?. Furthermore, the hydrodynamic diameters of the microemulsion droplets increase with increase in both X(Brij-35) and ?. Correlations of the results in terms of the evaluated physicochemical parameters have been attempted. PMID:23664388
Physicochemical investigation of mixed surfactant microemulsions: water solubilization, thermodynamic properties, microstructure, and dynamics.
Bardhan, Soumik; Kundu, Kaushik; Saha, Swapan K; Paul, Bidyut K
In this contribution, we report on a systematic investigation of phase behavior and solubilization of water in water-in-heptane or decane aggregates stabilized by mixtures of polyoxyethylene (20) cetyl ether (Brij-58) and cetyltrimethylammonium bromide (CTAB) surfactants with varying compositions in conjugation with 1-pentanol (Pn) at fixed surfactant(s)/Pn ratio and temperature. Synergism in water solubilization was evidenced by the addition of CTAB to Brij-58 stabilized system in close proximity of equimolar composition in both oils. An attempt has been made to correlate composition dependent water solubilization and volume induced conductivity studies to provide insight into the solubilization mechanism of these mixed systems. Conductivity studies reveal the ascending curve in water solubilization capacity-(Brij-58:CTAB, w/w) profile as the interdroplet interaction branch indicating percolation of conductance and the descending curve is a curvature branch due to the rigidity of the interface in these systems. The microstructure of these systems as a function of surfactant composition has been determined by dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FTIR) measurements. FTIR study reveals increase and decrease in relative population of bound and bulk-like water, respectively, with increase in Brij-58:CTAB (w/w). DLS measurements showed that the droplet hydrodynamic diameter (Dh) decreases significantly with the increase in Brij-58:CTAB (w/w). Further, the interfacial composition and energetic parameters for the transfer of Pn from bulk oil to the interface were evaluated by the dilution method. Formation of temperature-insensitive microemulsions and temperature invariant droplet sizes are evidenced in the vicinity of the equimolar composition. The results are interpreted in terms of a proposed mechanism. PMID:24064004
The dual effects of alcohols on the kinetic properties of guinea pig liver cytosolic beta-glucosidase.
Gopalan, V; Glew, R H; Libell, D P; DePetro, J J
This report demonstrates the effect of primary alcohols on the kinetic properties of guinea pig liver cytosolic beta-glucosidase. Lineweaver-Burk analyses of the kinetic data revealed a biphasic response; at low concentrations the alcohols increased the Vmax 5--7-fold while at higher concentrations they caused a purely competitive type of inhibition. For example, with n-butyl alcohol, increasing the alcohol's concentration in the assay medium from 0 to 0.14 M (0-1% (v/v)) resulted in a progressive increase in Vmax to a value 7-fold above the basal level without affecting the Km. However, between 0.14 and 0.54 M (1 and 4% (v/v)) n-butyl alcohol, the Km for 4-methylumbelliferyl-beta-D-glucopyranoside increased significantly from 0.14 to 0.93 mM. In contrast to n-butyl alcohol or isobutyl alcohol, which are potent activators, structurally related compounds like sec-butyl alcohol, tert-butyl alcohol, butylurea, and butanesulfonic acid did not stimulate the activity of the cytosolic beta-glucosidase. In the concentration range where activation was observed, conventional secondary replots of 1/delta slope versus 1/[alcohol] yielded perfect straight lines, demonstrating that binding of a single molecule of alcohol to the beta-glucosidase was responsible for the initial phase of activation. Furthermore, the glycohydrolase displayed a propensity to bind the longer chain alcohols, as reflected by the KA (binding constant) values of 555, 146, 34.1, and 7.47 mM for ethanol, n-propyl alcohol, n-butyl alcohol, 1-pentanol, respectively. This phenomenon of nonessential activation by alcohols has led us to speculate on the presence of a physiologic activator for the beta-glucosidase in mammalian tissues which contain this enzyme. PMID:2504720
Aliphatic ?-Nitroalcohols for Therapeutic Corneoscleral Cross-linking: Chemical Mechanisms and Higher Order Nitroalcohols
Solomon, Marissa R.; Wen, Quan; Turro, Nicholas J.; Trokel, Stephen L.
Purpose. The recent tissue cross-linking studies indicate that aliphatic ?-nitroalcohols (BNAs) may be useful as pharmacologic corneoscleral cross-linking agents. The present study was performed to identify the specific chemistry involved under physiologic conditions, with the intent of identifying more effective agents. Methods. The mechanism of chemical cross-linking at pH 7.4 and 37░C was studied using three techniques. The colorimetric Griess assay was used to follow the release of nitrite from three mono-nitroalcohols (2-nitroethanol [2ne], 2-nitro-1-propanol [2nprop]), and 3-nitro-2-pentanol [3n2pent]). Second, the evolution of 2nprop in 0.2 M NaH2PO4/Na2HPO4/D2O was studied using 1H-NMR. Third, thermal shrinkage temperature analysis (Ts), a measure of tissue cross-linking, was used to support information from 1the H-NMR studies. Results. A time-dependent release of nitrite was observed for all three mono-nitroalcohols studied. The maximum levels were comparable using either 2ne or 2nprop (?30%). However, much less (?10%) was observed from 3n2pent. Using 1H-NMR, 2nprop evolved into a unique splitting pattern. No match was observed with reference spectra from three possible products of denitration. In contrast, 2-methyl-2-nitro-1,3-propanediol (MNPD), a nitro-diol, was identified, implying the formation of formaldehyde from a retro-nitroaldol (i.e., reverse Henry) reaction. In support of this mechanism, Ts shifts induced by the nitro-triol 2-hydroxymethyl-2-nitro-1,3-propanediol (HNPD) were superior to the nitro-diol MNPD which were superior to the mono nitroalcohol 2nprop. Conclusions. BNAs function as both formaldehyde and nitrite donors under physiologic conditions to cross-link collagenous tissue. Higher order BNAs are more effective than mono nitroalcohols, raising the possibility of using these agents for therapeutic corneoscleral cross-linking. PMID:19797229
Airborne molds and bacteria, microbial volatile organic compounds (MVOC), plasticizers and formaldehyde in dwellings in three North European cities in relation to sick building syndrome (SBS).
Sahlberg, Bo; Gunnbj÷rnsdottir, Maria; Soon, Argo; Jogi, Rain; Gislason, Thorarinn; Wieslander, Gunilla; Janson, Christer; Norback, Dan
There are few studies on associations between airborne microbial exposure, formaldehyde, plasticizers in dwellings and the symptoms compatible with the sick building syndrome (SBS). As a follow-up of the European Community Respiratory Health Survey (ECRHS II), indoor measurements were performed in homes in three North European cities. The aim was to examine whether volatile organic compounds of possible microbial origin (MVOCs), and airborne levels of bacteria, molds, formaldehyde, and two plasticizers in dwellings were associated with the prevalence of SBS, and to study associations between MVOCs and reports on dampness and mold. The study included homes from three centers included in ECRHS II. A total of 159 adults (57% females) participated (19% from Reykjavik, 40% from Uppsala, and 41% from Tartu). A random sample and additional homes with a history of dampness were included. Exposure measurements were performed in the 159 homes of the participants. MVOCs were analyzed by GCMS with selective ion monitoring (SIM). Symptoms were reported in a standardized questionnaire. Associations were analyzed by multiple logistic regression. In total 30.8% reported any SBS (20% mucosal, 10% general, and 8% dermal symptoms) and 41% of the homes had a history of dampness and molds There were positive associations between any SBS and levels of 2-pentanol (P=0.002), 2-hexanone (P=0.0002), 2-pentylfuran (P=0.009), 1-octen-3-ol (P=0.002), formaldehyde (P=0.05), and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (Texanol) (P=0.05). 1-octen-3-ol (P=0.009) and 3-methylfuran (P=0.002) were associated with mucosal symptoms. In dwellings with dampness and molds, the levels of total bacteria (P=0.02), total mold (P=0.04), viable mold (P=0.02), 3-methylfuran (P=0.008) and ethyl-isobutyrate (P=0.02) were higher. In conclusion, some MVOCs like 1-octen-3-ol, formaldehyde and the plasticizer Texanol, may be a risk factor for sick building syndrome. Moreover, concentrations of airborne molds, bacteria and some other MVOCs were slightly higher in homes with reported dampness and mold. PMID:23280302
An efficient and general route to reduced polypropionates via Zr-catalyzed asymmetric CŚC bond formation
Negishi, Ei-ichi; Tan, Ze; Liang, Bo; Novak, Tibor
An efficient and general method for the synthesis of reduced polypropionates has been developed through the application of asymmetric carboalumination of alkenes catalyzed by dichlorobis(1-neomenthylindenyl)zirconium [(NMI)2ZrCl2]. In this investigation, attention has been focused on those reduced polypropionates that are ?-monoheterofunctional and either ?-ethyl or ?-n-propyl. The reaction of 3-buten-1-ol with triethylaluminum (Et3Al) or tripropylaluminum (nPr3Al) in the presence of (NMI)2ZrCl2 and isobutylaluminoxane gave, after protonolysis, (R)-3-methyl-1-pentanol as well as (R)- and (S)-3-methyl-1-hexanols in 88¢92% yield in 90¢92% enantiomeric excess in one step. These 3-monomethyl-1-alkanols were then converted to two stereoisomers each of 2,4-dimethyl-1-hexanols and 2,4-dimethyl-1-heptanols via methylalumination catalyzed by (NMI)2ZrCl2 and methylaluminoxane followed by oxidation with O2. The four-step (or three-isolation-step) protocol provided syn-2,4-dimethyl-1-alkanols of ?98% stereoisomeric purity in ?50% overall yields, whereas (2S,4R)-2,4-dimethyl-1-hexanol of comparable purity was obtained in 40% overall yield. Commercial availability of (S)-2-methyl-1-butanol as a relatively inexpensive material suggested its use in the synthesis of (2S,4S)- and (2R,4S)-2,4-dimethyl-1-hexanols via a three-step protocol consisting of (i) iodination, (ii) zincation followed by Pd-catalyzed vinylation, and (iii) Zr-catalyzed methylalumination followed by oxidation with O2. This three-step protocol is iterative and applicable to the synthesis of reduced polypropionates containing three or more branching methyl groups, rendering this method for the synthesis of reduced polypropionates generally applicable. Its synthetic utility has been demonstrated by preparing the side chain of zaragozic acid A and the C11¢C20 fragment of antibiotics TMC-151 A¢F. PMID:15073327
A Combinatorial Polymer Library Approach Yields Insight into Nonviral Gene Delivery
CONSPECTUS The potential of gene therapy to benefit human health is tremendous because almost all human diseases have a genetic component, from untreatable monogenic disorders to cancer and heart disease. Unfortunately, a method for gene therapy that is both effective and safe has remained elusive. It has been said that ōthere are only three problems in gene therapy - delivery, delivery, and delivery.ö (quote from I. M. Verma in Jaroff, L. TIME, 1999; Jan 11). This Account describes an alternative strategy to viral gene delivery: the design of biodegradable polymers that are able to deliver DNA like a synthetic virus. Using high-throughput synthesis and screening techniques, we have created libraries of over 2000 structurally unique poly(?-amino esters) (PBAEs). PBAEs are formed by the conjugate addition of amines to diacrylates. These biomaterials are promising for nonviral gene delivery due to their ability to condense plasmid DNA into small and stable nanoparticles and their ability to promote cellular uptake and endosomal escape. Our laboratory has iteratively improved PBAE nanoparticles through polymer end modifications and nanoparticle coatings. Lead PBAEs have high gene delivery efficacy and low cytotoxicity both in vitro and in vivo. Certain polymer structural characteristics are important for effective gene delivery. The best PBAEs are linear polymers of ~10 kDa that contain hydroxyl side chains and primary amine end groups. These polymers bind DNA to form nanoparticles that are small (<200 nm) and stable and have near-neutral ?potential in the presence of serum-containing media. Lead PBAEs also contain tertiary amines that can buffer the low pH environment of endosomes and facilitate escape of polymer/DNA particles into the cytoplasm. Diamine end-modified 1,4-butanediol diacrylate-co-5-amino-1-pentanol polymers (C32) bind DNA more tightly and form smaller nanoparticles than other PBAEs. These nanoparticles also have higher cellular uptake and the best gene expression of all gene delivery polymers in the library. These polymers are more effective for gene delivery than top commercially available nonviral vectors including jet-PEI and Lipofectamine 2000 and are comparable to adenovirus for in vitro gene delivery to human primary cells. In vivo, these PBAE/ DNA particles are promising as cancer therapeutics. This Account summarizes the results of our laboratory in using a combinatorial polymer library approach to elucidate polymer structure/function relationships and enable the development of polymeric gene delivery nanoparticles with viral-like efficacy. PMID:18507402
The effect of cavitating ultrasound on the aqueous phase hydrogenation of cis-2-buten-1-ol and cis-2-penten-1-ol on Pd-black
Disselkamp, Robert S.; Denslow, Kayte M.; Hart, Todd R.; White, James F.; Peden, Charles HF.
We have studied the effect of cavitating ultrasound on the heterogeneous aqueous hydrogenation of cis-2-buten-1-ol (C4 olefin) and cis-2-penten-1-ol (C5 olefin) on Pd-black to form the trans-olefins (trans-2-buten-1-ol and trans-2-penten-1-ol) and saturated alcohols (1-butanol and 1-pentanol, respectively). Silent (and magnetically stirred) experiments served as control experiments. As described in an earlier publication by our group, we have added an inert dopant, 1-propanol, in the reaction mixture to ensure the rapid onset of cavitation in the ultrasound-assisted reactions that can lead to altered selectivity compared to silent reaction systems [R.S. Disselkamp, Ya-Huei Chin, C.H.F. Peden, J. Catal. 227 (2004) 552]. The motivation for this study is to examine whether cavitating ultrasound can reduce the [trans-olefin/saturated alcohol] molar ratio during the course of the reaction. This could have practical application in that it may offer an alternative processing methodology of synthesizing healthier edible seed oils by reducing trans-fat content.We have observed that cavitating ultrasound results in a [(trans-olefin/saturated alcohol)ultrasound/(trans-olefin/saturated alcohol)silent] ratio quantity less than 0.5 at the reaction mid-point for both the C4 and C5 olefin systems. This indicates that ultrasound reduces trans-olefin production compared to the silent control experiment. Furthermore, there is an added 30% reduction for the C5 versus C4 olefin compounds again at reaction mid-point. We attribute differences in the ratio quantity as a moment of inertia effect. In principle, the C4 versus C5 olefins has a {approx}52% increase in moment of inertia about C2 C3 double bond slowing isomerization. Since seed oils are C18 multiple cis-olefins and have a moment of inertia even greater than our C5 olefin here, our study suggests that even a greater reduction in trans-olefin content may occur for partial hydrogenation of C18 seed oils.
The Effect of Cavitating Ultrasound on the Aqueous Phase Hydrogenation of Cis-2-buten-1-ol and Cis-2-penten-1-ol on Pd-black
Disselkamp, Robert S.; Denslow, Kayte M.; Hart, Todd R.; White, James F.; Peden, Charles HF.
We have studied the effect of cavitating ultrasound on the heterogeneous aqueous hydrogenation of cis-2-buten-1-ol (C4 olefin) and cis-2-penten-1-ol (C5 olefin) on Pd-black to form the trans-olefins (trans-2-buten-1-ol and trans-2-penten-1-ol) and saturated alcohols (1-butanol and 1-pentanol, respectively). Silent (and magnetically stirred) experiments served as control experiments. As described in an earlier publication by our group, we have added an inert dopant, 1-propanol, in the reaction mixture to ensure the rapid onset of cavitation in the ultrasound-assisted reactions that can lead to altered selectivity compared to silent reaction systems [Disselkamp et al., J. Catal., 227 (2004) 552]. The motivation for this study is to examine whether cavitating ultrasound can reduce the [trans-olefin/saturated alcohol] molar ratio during the course of the reaction. This could have practical application in that it may offer an alternative processing methodology of synthesizing healthier edible seed oils by reducing trans-fat content. We have observed that cavitating ultrasound results in a [(trans-olefin/saturated alcohol)ultrasound/(trans-olefin/saturated alcohol)silent] ratio quantity less than 0.5 at the reaction mid-point for both the C4 and C5 olefin systems. This indicates that ultrasound reduces trans-olefin production compared to the silent control experiment. Furthermore, there is an added 30% reduction for the C5 versus C4 olefin compounds again at reaction mid-point. We attribute differences in the ratio quantity as a moment of inertia effect. In principle, the C4 versus C5 olefins has a {approx}52% increase in moment of inertia about C2=C3 double bond slowing isomerization. Since seed oils are C18 multiple cis olefins and have an moment of inertia even greater than our C5 olefin here, our study suggests that even a greater reduction in trans-olefin content may occur for partial hydrogenation of C18 seed oils.
Methanomassiliicoccus luminyensis gen. nov., sp. nov., a methanogenic archaeon isolated from human faeces.
Dridi, Bķdis; Fardeau, Marie-Laure; Ollivier, Bernard; Raoult, Didier; Drancourt, Michel
During attempts to obtain novel, human-associated species of the domain Archaea, a coccoid micro-organism, designated strain B10(T), was isolated in pure culture from a sample of human faeces collected in Marseille, France. On the basis of its phenotypic characteristics and 16S rRNA and mcrA gene sequences, the novel strain was classified as a methanogenic archaeon. Cells of the strain were non-motile, Gram-staining-positive cocci that were approximately 850 nm in diameter and showed autofluorescence at 420 nm. Cells were lysed by 0.1% (w/v) SDS. With hydrogen as the electron donor, strain B10(T) produced methane by reducing methanol. The novel strain was unable to produce methane when hydrogen or methanol was the sole energy source. In an atmosphere containing CO(2), strain B10(T) could not produce methane from formate, acetate, trimethylamine, 2-butanol, 2-propanol, cyclopentanol, 2-pentanol, ethanol, 1-propanol or 2,3-butanediol. Strain B10(T) grew optimally with 0.5-1.0% (w/v) NaCl, at pH 7.6 and at 37 ░C. It required tungstate-selenite for growth. The complete genome of the novel strain was sequenced; the size of the genome was estimated to be 2.05 Mb and the genomic DNA G+C content was 59.93 mol%. In phylogenetic analyses based on 16S rRNA gene sequences, the highest sequence similarities (98.0-98.7%) were seen between strain B10(T) and several uncultured, methanogenic Archaea that had been collected from the digestive tracts of a cockroach, a chicken and mammals. In the same analysis, the non-methanogenic 'Candidatus Aciduliprofundum boonei' DSM 19572 was identified as the cultured micro-organism that was most closely related to strain B10(T) (83.0% 16S rRNA gene sequence similarity). Each of the three treeing algorithms used in the analysis of 16S rRNA gene sequences indicated that strain B10(T) belongs to a novel order that is distinct from the Thermoplasmatales. The novel strain also appeared to be distinct from Methanosphaera stadtmanae DSM 3091(T) (72.9% 16S rRNA gene sequence similarity), another methanogenic archaeon that was isolated from human faeces and can use methanol in the presence of hydrogen. Based on the genetic and phenotypic evidence, strain B10(T) represents a novel species of a new genus for which the name Methanomassiliicoccus luminyensis gen. nov., sp. nov. is proposed. The type strain of the type species is B10(T) (?=?DSM 24529(T)?=?CSUR P135(T)). PMID:22859731
A Unique Equation to Estimate Flash Points of Selected Pure Liquids Application to the Correction of Probably Erroneous Flash Point Values
NASA Astrophysics Data System (ADS)
Catoire, Laurent; Naudet, Valķrie
A simple empirical equation is presented for the estimation of closed-cup flash points for pure organic liquids. Data needed for the estimation of a flash point (FP) are the normal boiling point (Teb), the standard enthalpy of vaporization at 298.15 K [?vapH░(298.15 K)] of the compound, and the number of carbon atoms (n) in the molecule. The bounds for this equation are: -100?FP(░C)?+200; 250?Teb(K)?650; 20??vap H░(298.15 K)/(kJ mol-1)?110; 1?n?21. Compared to other methods (empirical equations, structural group contribution methods, and neural network quantitative structure-property relationships), this simple equation is shown to predict accurately the flash points for a variety of compounds, whatever their chemical groups (monofunctional compounds and polyfunctional compounds) and whatever their structure (linear, branched, cyclic). The same equation is shown to be valid for hydrocarbons, organic nitrogen compounds, organic oxygen compounds, organic sulfur compounds, organic halogen compounds, and organic silicone compounds. It seems that the flash points of organic deuterium compounds, organic tin compounds, organic nickel compounds, organic phosphorus compounds, organic boron compounds, and organic germanium compounds can also be predicted accurately by this equation. A mean absolute deviation of about 3 ░C, a standard deviation of about 2 ░C, and a maximum absolute deviation of 10 ░C are obtained when predictions are compared to experimental data for more than 600 compounds. For all these compounds, the absolute deviation is equal or lower than the reproductibility expected at a 95% confidence level for closed-cup flash point measurement. This estimation technique has its limitations concerning the polyhalogenated compounds for which the equation should be used with caution. The mean absolute deviation and maximum absolute deviation observed and the fact that the equation provides unbiaised predictions lead to the conclusion that several flash points have been reported erroneously, whatever the reason, in one or several reference compilations. In the following lists, the currently accepted flash points for bold compounds err, or probably err, on the hazardous side by at least 10 ░C and for the nonbolded compounds, the currently accepted flash points err, or probably err, on the nonhazardous side by at least 10 ░C: bicyclohexyl, sec-butylamine, tert-butylamine, 2-cyclohexen-1-one, ethanethiol, 1,3-cyclohexadiene, 1,4-pentadiene, methyl formate, acetonitrile, cinnamaldehyde, 1-pentanol, diethylene glycol, diethyl fumarate, diethyl phthalate, trimethylamine, dimethylamine, 1,6-hexanediol, propylamine, methanethiol, ethylamine, bromoethane, 1-bromopropane, tert-butylbenzene, 1-chloro-2-methylpropane, diacetone alcohol, diethanolamine, 2-ethylbutanal, and formic acid. For some other compounds, no other data than the currently accepted flash points are available. Therefore, it cannot be assessed that these flash point data are erroneous but it can be stated that they are probably erroneous. At least, they need experimental re-examination. They are probably erroneous by at least 15 ░C: 1,3-cyclopentadiene, di-tert-butyl sulfide, dimethyl ether, dipropyl ether, 4-heptanone, bis(2-chloroethyl)ether, 1-decanol, 1-phenyl-1-butanone, furan, ethylcyclopentane, 1-heptanethiol, 2,5-hexanediol, 3-hexanone, hexanoic acid methyl ester, 4-methyl-1,3-pentadiene, propanoyl chloride, tetramethylsilane, thiacyclopentane, 1-chloro-2-methyl-1-propene, trans-1,3-pentadiene, 2,3-dimethylheptane, triethylenetetramine, methylal, N-ethylisopropylamine, 3-methyl-2-pentene, and 2,3-dimethyl-1-butene.
Decontamination of Tritiated-Water Using Super-hydrophobic Pt-Catalyst Synthesized with Water-in-Supercritical CO{sub 2}
Youichi Enokida; Kayo Sawada [EcoTopia Science Institute (Japan)]|[Graduate School of Engineering, Nagoya University, 1 furo-cho, Nagoya 463-8603, Aichi-ken (Japan); Ryosuke Shimizu [EcoTopia Science Institute (Japan); Ichiro Yamamoto [Graduate School of Engineering, Nagoya University, 1 furo-cho, Nagoya 463-8603, Aichi-ken (Japan)
Tritium, {sup 3}H, is one of the hydrogen isotopes, created in coolant of a fission reactor and to be utilized as fuel for nuclear fusion reactors. Since a large amount of tritium will be contained in a fusion reactor or in a fission reactor, a small fraction of the tritiated chemical species, in most cases, tritiated water, may leak to the environment. Tritium is, however, a radioactive isotope whose specific radioactivity is 4 x 10{sup 17} Bq kg{sup -1}, and easy to transfer in human body, its confinement is very important from the safety aspect. One of the problems of tritium confinement and decontamination of tritiated chemical species is related with necessity of its isotope separation from lighter hydrogen isotopes, {sup 2}H and {sup 1}H. Most of principles for the isotope separations are based on fractionations of isotopes in different chemical species. A large fractionation for hydrogen isotopes is observed in a chemical exchange of hydrogen atoms between water, Q{sub 2}O, and hydrogen gas, Q{sub 2}, where 'Q' denotes one of the hydrogen isotopes. Heavier isotopes are enriched significantly into Q{sub 2}O rather than Q{sub 2}. Therefore practical method of tritium removal would be established by hydrogen isotope separation with chemical exchange of water and hydrogen gas. At first, we prepared a catalyst, by reducing Pt{sup 4+} in reversed micelles where the reducing agent, aqueous solution of sodium tetra borohydrate, NaBH{sub 4} was also contained in reversed micelles prepared separately. In this situation, micelles containing Pt{sup 4+} and reducing reagent collided and produced Pt nanoparticles, which were expected to be impregnated in the hydrophobic structure after depressurization. After this type of earlier experiment we determined a mass of impregnated Pt by total dissolution of gauze with aqua regia followed by concentration measurement of Pt with ICP-AES. We performed several trials, unfortunately, however, the mass of Pt deposited on the gauze was very small to detect, and this approach turns to be not successful. As the second approach, we utilize CO{sub 2} soluble Pt precursor, CODMe{sub 2}Pt purchased from Sigma-Aldrich Co. and H{sub 2} gas as reducing agent, which could be completely mixed with SC-CO{sub 2}. This system was well-known for Pt particle formation by auto-catalytic growth. The second approach was aiming at increasing Pt amount deposited in the gauze. This approach was successful in increasing Pt amount, but the Pt particle size also increased to be more than 50 nm, which was not suitable for catalyst. Finally, we synthesized the catalyst by the following procedure: firstly, a reducing agent of NaBH{sub 4} was deposited on the nano-textured hydrophobic layer on the gauze. This step was realized by forming reversed micelles of aqueous NaBH{sub 4} solution using a surfactant AOT and a co-surfactant 2,2,3,3,4,4,5,5,-octafluoro-1-pentanol (F-pentanol) in SC-CO{sub 2}. This system of surfactant combination of AOT and F-pentanol has been found to work successfully in recent studies. In the second step, the gauze was contacted with CODMe{sub 2}Pt dissolved in SC-CO{sub 2} to synthesize seeds of Pt particles for the auto-catalytic reaction proceeding by CODMe{sub 2}Pt with hydrogen. The seeds were formed by the reaction between deposited NaBH{sub 4} and CODMe{sub 2}Pt in SC-CO{sub 2}. The physical characterization of this catalyst was performed by SEM-EDS. By this procedure, the Pt hydrophobic catalyst where Pt nanoparticle of 10 nm in diameter was locally deposited in the nano-textured layer was successfully prepared. Hydrophobicity after the chemical Pt deposition was tested by measurement of water absorbed on the gauze and the catalyst performance was evaluated by {sup 1}H{sup 2}H formation through the scrambling reaction from {sup 1}H{sub 2} and {sup 2}H{sub 2} and the reaction was successfully observed. We demonstrated a new hydrophobic catalyst preparation using SC-CO{sub 2} effectively. We can conclude that the approach of creating Pt nanoparticles in SC-CO{sub 2} and depositing them in